Help:Sorting

src: c8.alamy.com

Video Help:Sorting

Using sortable tables

When browsing Wikipedia you may encounter tables that have been made sortable. A sortable table is identified by the arrows in one or more of its header cells. Clicking them will cause the table rows to sort based on the selected column, in ascending order first, and subsequently toggling between ascending and descending order.

The actual sorting process will happen on your computer using client-side JavaScript. For this reason it is only possible to use this functionality if you have JavaScript enabled in your web browser. The sorting process is also dependent on your computer and the amount of data. Sorting a very large table on a slow computer may take quite long.

Example

This is an example of a small sortable table.

Tables with complex headers

Tables with more complex headers than before now sort correctly. For example:

Tables with complex datarows

Tables can have cells spanning multiple rows, using |rowspan=n. (See Help:rowspan).

The number of rows must be indicated with each use of rowspan. Before any sorting can be done, the rowspan setup must be correct. An incorrect rowspan organisation breaks sorting option, leaving incorrect data.

See examples below.

When sorted all the rows are filled. Tables without rowspan are much easier to maintain by less experienced editors, and by editors who are stopping by only once to edit the table.

Correct rowspan numbers, with sorting in working order:

Note that, after sorting, the rowspanning cells are cut into rows and their content is repeated (the year "2014" in the example).

Incorrect rowspan numbers breaking sorting, and causing mix-ups in rows and columns:

Online table editors and rowspan

There is an easy online wiki table editor here:

• wikitable.eu5.org

It makes it easy to edit the text and links in individual cells of a table. It is especially easy when there are no rowspans in the body of a table. See the previous section. Without rowspans it is easier to change the underlying framework of a table, and move stuff around. Once the wikitext framework is simpler, the online table editor is simpler too, because you don't have to edit the wikitext as much in order to edit the table.

In a narrow space: sorting buttons in a separate row

To make a table more compact in narrow screens, the sorting buttons can be put in an extra header row below the header cells containing text. The sorting button always ends up in the lowest header cell.

Add a line break <br> or non-breaking space   in one of the empty header cells. Otherwise the sorting row will be very narrow. Here is the table followed by the wikitext for the header cells.

  {| class="wikitable sortable"  |-  ! rowspan="2" | name  ! colspan="2" | data columns  ! rowspan="2" | another column  |-  ! data  ! more data  |-  ! <br>!! !! !!  |-  

Secondary key

If a column contains a value multiple times then sorting the column preserves the order of the rows within each subset that has the same value in that column (stable sorting). Thus sorting based on a primary, secondary, tertiary, etc. key can be done by sorting the least-significant key first, etc. For example, to sort the table below on the Text column, then the Numbers column, first click on the "Numbers" column heading (the secondary sort key), then the "Text" column heading (the primary sort key).

Another way to sort a table using multiple sort keys is to hold down the shift key while clicking on the column headings for the subsequent sort keys. For example, to sort the table below on the Text column, then the Numbers column, first click on the "Text" column heading (the primary sort key), then hold down the shift key and click on the "Numbers" column heading (the secondary sort key).

Maps Help:Sorting

Creating sortable tables

Tables can be made sortable via client-side JavaScript by adding class="wikitable sortable" to their top line. These tables need to be properly formatted, with the right amount of cells. Additionally you need to make sure that the headers of your column are properly indicated in the wikicode. For this the ! character is used in the table syntax.

If you are using the Visual editor, you can open the properties dialog of a table and select the sortable option.

Simple example

This is the wikisource of the table shown in the first section and shows the typical way to enable table sorting:

  {| class="wikitable sortable"  |-  ! name  ! data  ! more data  |-  | cats  | 273  | 53  |-  | dogs  | 65  | 8,492  |-  | mice  | 1,649  | 548  |}  

The ! indicates cells that are header cells. In order for a table to be sortable, the first row(s) of a table need to be entirely made up out of these header cells. You can learn more about the basic table syntax by taking the Introduction to tables.

Initial sort order of rows

When users are first presented with a table, the rows will always appear in the same order as in the wikitext. If you want a table to appear sorted by a certain column, you must sort the wikitext itself in that order. This is usually done for the first column. The VisualEditor makes it easy to move individual table columns and rows around. For info about that, and also about putting a table in initial alphabetical order see the relevant section here.

Restrictions

• Tables can only click-to-sort vertically downwards (clicking on a topmost-column-name will cause the rows of the table to re-order themselves in their up-and-down positions). It is not possible to click-to-sort horizontally across (there is no way to click on a leftmost-row-cell so as to cause the columns of the table to re-order themselves in their left-to-right positions).

Making a column unsortable

If you want a specific column not to be sortable, specify class="unsortable" in the attributes of its header cell.

Wiki markup

  {|class="wikitable sortable"  !Numbers!!Alphabet!!Dates!!Currency!!class="unsortable"|Unsortable  |-  |1||Z||02-02-2004||5.00||This  |-  |2||y||13-apr-2005||||Column  |-  |3||X||17.aug.2006||6.50||Is  |-  |4||w||01.Jan.2005||4.20||Unsortable  |-  |5||V||05/12/2006||7.15||See?  |-  !Total: 15!!!!!!Total: 22.85!!  |}  

What it looks like in your browser

src: i.ytimg.com

Configuring the sorting

Forcing a column to have a particular data type

The data-sort-type="..." attribute can be added inside the header of a column to ensure that the cells underneath are all treated as a specified type of data.

The following (case-insensitive) values are valid for data-sort-type:

• text
• number
• currency
• url for website addresses
• IPAddress for numeric internet protocol addresses
• date for language specific standard date format.
• isoDate for dates in the ISO YYYY-MM-DD format.
• usLongDate for dates in the US format (with the month before the day)
• time

For example:

Without data-sort-type="text" in the header, the tablesorter gets confused by the numeric titles in the first few rows into treating the entire column as numeric. This results in it wrongly sorting the non-numeric titles as zero regardless of the alphabetical ordering of their text.

Note that if a column without declared sort-type contains only numeric values, but with a reference <ref>...</ref> immediately after the last digit of at least one number, this may cause the column to be sorted as text (alphanumeric) by default, 1 12 2 27 289 3[17] 4 5 ... This can be avoided by declaring the sort type:! data-sort-type="number"|Elev. (ft) instead of ! Elev. (ft).

Default data type of a column

If you do not specify a data-sort-type, the sort modes (the data types, which, in addition to the choice "ascending" or "descending", determine the sorting order) are as follows:

• date (see also below)
  • criterion: the first non-blank element is of the form "DD-MM-YYYY", "DD-MM-YY", or "DD mmm YYYY"
  • order: numeric value of YYYYMMDD; The string DDsMMsYYYY of length 10 (if characters positioned at s are equal together and are either '/' or '-' separator) is positioned as YYYYMMDD, the string DDsMMsYY of length 8 (if characters positioned at s are equal together and are either '/' or '-' separator) as 19YYMMDD if YY >= 50 and 20YYMMDD otherwise, and the string "DD mmm YYYY" with mmm an (abbreviated) month name.
• isoDate (ISO 8601)
  • criterion: format "±YYYY-MM-DD", with 1-4 digits for year "YYYY" from -9999 to 9999, month only with digits, format "±YYYY-MM-DDThh:mm:ss.sss±TH:TM" with time hour "hh", minutes "mm", seconds "ss.sss", and time zone offset "TH:TM, right values are optional.
  • order: numeric, with time in milliseconds after 01 January, 1970 UTC.
• "currency" (this mode can be useful for other data also)
  • criterion: the first non-blank element starts with $, £, EUR, or ¥
  • order: numeric, ignoring these symbols and all ordinary letters and commas, but not spaces; note that scientific notation cannot be used, as e and E are removed
• numeric
  • criterion: the first non-blank element consists of just digits, points, commas, spaces, "+", "-", possibly followed by "e" or "E" and a string consisting of "+", "-", digits
  • order: after removing the commas and spaces, if any, if the string starts with a number the order is numeric according to the first number in the string (parseFloat is applied); it is regarded as zero if it is empty; in other cases (parseFloat returns NaN), the element is positioned like -?.

proposed internationalisation: in German etc., treat comma as a decimal point

• string
  • criterion: all other cases; to avoid one of the other modes, start e.g. with a hidden "&"; this can be done conveniently with m:Template:sms (backlinks edit), which also allows more hidden text, as a sort key; while the similar templates above are called at the end of a table element, call this one at the start
  • order: after conversion of capitals to lowercase the order is ASCII - partial list showing the order: !"#$%&'()*+,-./09:;<=>?@[\]^_'az{|}~é-- (see also below; a blank space comes before every other character; a non-breaking space code   counts as a space; two adjacent ordinary blank spaces count as one; for multiple blank spaces one can use   or alternate   and ordinary blank spaces)

If more than one possible type matches, the first type in the above order is chosen. For example, "24-12-2007" matches as a date, so is not treated as a number. Formatting and markup tags are ignored when determining the matching type.

The sort mode is determined by the first 5 non-blank rows below the header after loading the page. This can also change after deleting a row, or adding a column. Therefore it is wise to make sure that every element matches the criterion for the required data type. Using a row template this can be done very conveniently.

The method of making sure the sort mode of each column is as desired, is specify a data-sort-type, see up.

Specifying a sort key for a cell

Sometimes the value of a cell is not correctly parsed or one wants to sort the row in a special way. (e.g. a cell containing 'John Doe' should actually be sorted as 'Doe' and not as 'John'). This can be easily achieved by setting the data-sort-value attribute.

Wiki markup

  {|class="wikitable sortable"  !Name and Surname!!Height  |-  |data-sort-value="Smith, John"|John Smith||1.85  |-  |data-sort-value="Ray, Ian"|Ian Ray||1.89  |-  |data-sort-value="Bianchi, Zachary"|Zachary Bianchi||1.72  |-  !Average:||1.82  |}  

This gives:

It is especially handy to sort military ranks in rank-seniority order.

Wiki markup

  {|class="wikitable sortable"  !Name and Surname!!Rank  |-  |data-sort-value="Smith, John"|John Smith||data-sort-value="16"|[[Corporal|Cpl]]  |-  |data-sort-value="Ray, Ian"|Ian Ray||data-sort-value="8"|[[Captain (OF-2)|Capt]]  |-  |data-sort-value="Bianchi, Zachary"|Zachary Bianchi||data-sort-value="10"|[[2nd Lieutenant|2 Lt]]  |}  

This gives:

See also mw:Help:Sorting#Specifying a sort key.

If you have a list where all the entries start with quotes ("), and you want to set a sort key for one of the entries, then you will need to use the HTML name or number for quotes at the beginning of that sort key. See here too. Lists of song titles for example sometimes have each song title in quotes. So to sort by a particular word in a song title use one of these:

data-sort-value=""WORD"

data-sort-value=""WORD"

Keeping some rows together

data-sort-value can be used to keep certain rows together. The specified order of these rows is preserved. An example is to keep "South Holland" immediately after "Netherlands", whatever the sort order or column:

If you have rows that contain colspans, this might become a little difficult. You can also use the class="expand-child" on a row; it will then always be below the row just above it in the table source, wherever that row may be sorted in the table.

src: c8.alamy.com

Dealing with problems

Numerical sorting problems

Normally, text breaks default numerical sorting whether the text is before or after the number, even if it is a reference <ref>...</ref>. The {{N/A}} template in any cell in a numerical column breaks numerical sorting of that column. This problem with {{N/A}} can be fixed by putting data-sort-type="number" in the column header,

Even when using data-sort-type="number" in the column header, text in front of a number in any cell breaks numerical sorting. Text after a number is not a problem if the sort order of a column is specified by using data-sort-type="number".

A dash, of any kind, in a blank cell breaks numerical sorting of a column. A dash is only allowed in front of a number. Dashes are allowed anywhere in cells if data-sort-type="number" is used in the column header.

A dash after a number breaks numerical sorting of a column. Therefore a range (30-40) breaks numerical sorting of a column. Click the sorting button in the first table to the right, and see that sorting does not work. One solution is to use 2 columns for a range. See and experiment with preview views of the table in 15 October 2011 global protests. Using two columns there allows one to sort by either the minimum estimated crowd sizes, or by the maximum estimated crowd sizes.

Another option is to use one column and add data-sort-type="number" in the column header. Click the sorting button in the table to the far right. For more info see meta:Help:Sorting#Sort modes and the section about forcing the sort mode for a column.

A plus sign (+) in front of a number does not break numerical sorting of a column. A plus sign in an otherwise empty cell can break numerical sorting of a column if the first non-empty cell going down a column consists of just a plus sign. A plus sign after a number can break numerical sorting if the first non-empty cell going down a column consists of a number followed by a plus sign. See and experiment with preview views of the table in 15 October 2011 global protests.

References immediately after numbers, like 12345<ref>Hoyle 2002</ref>, currently break numerical sorting of a column. For example; compare these 2 versions of an article: [1] [2]. One has a reference in the "Wins" column and one does not. These before and after examples illustrate the effect of forcing numerical sorting without removing the references (sort the List of peaks by number by the Elevation column, 4049 shows as higher than 18035 with default sort type). If data-sort-type="number" is used in the column header then references are OK after numbers.

"c." (circa, indicates "approximately") is often found in columns of numbers. It needs to be moved to a different column. Or if data-sort-type="number" is used in the column header then "c." can be put after the number.

Leading zeroes are not necessary for numerical sorting of a column. If it seems that way, then that means the column is being sorted alphabetically. Check for cells with anything other than numbers, and correct those cells according to the above rules.

Date sorting problems

There is now a way to manually force a column to sort by date. This is done by adding data-sort-type="date" to the column header. See the cases where this is necessary below.

Year only

See List of countries by income equality. Year sorting of a column works as long as no text is the first thing in a cell in the column. The year must be first. Text is OK after a year in a cell. References after the year are OK.

A dash, of any kind, in a blank cell breaks year sorting of a column. Dashes after the year are OK.

Unlike for numerical sorting the {{N/A}} template in any cell in a year column does not break year sorting of that column.

If there are problems with year sorting check for any cells in the column with text or a dash (of any kind) as the first thing in a cell. Remove that text or dash to return the column to correct year sorting.

Year and month

Date sorting does not work for columns with only the year before the month (no day). Adding data-sort-type="date" or data-sort-type="isoDate" to the column header does not help. Click each column header a couple times in the tables below to see. Note the column headed data-sort-type="isoDate" may sort correctly in some browsers, but it is not reliable.
Year/month/day works (not Year Month), with data-sort-type="isoDate" (see relevant section farther down).

Month and year

Date sorting does not work for columns with only the month before the year (no day). Adding data-sort-type="date" to the column header does not help.

Day, month, and year

Sorting works correctly in all cases below. Years before 100 break sorting. For example; year 99. If a number for a day is missing, sorting is broken.

Month, day, and year

Sorting works correctly in all the tables below. Years before 100 (for example, year 99) break sorting. If a number for a day is missing, sorting is broken.

Year, month, and day

Sorting only works correctly with data-sort-type="isoDate". Former years 0...99 break sorting. Since August 2017 this is solved and improved. Short forms are possible: JJJJ, JJJJ-MM, prefixes and postfixes allowed.

Day and month

These dates use the {{Dts}} template. See the wikitext ("edit source"). Note none of the table columns use the 'data-sort-type=' modifier. Using 'data-sort-type=' can sometimes break sorting.

Years before year 100

Non-date keys like "number" or "isoDate" are the only option. For example; with data-sort-type="isoDate". Sorting is done via the hidden data-sort-value isoDate:

year-mm-dd.

  {| class="wikitable sortable"  |-  ! data-sort-type="isoDate" | Date  |-  | data-sort-value="111-12-05" | 5 Dec 111  |-  | data-sort-value="35-01-07" | 7 Jan 35  |-  | data-sort-value="207-12-05" | 5 Dec 207  |-  | data-sort-value="-111-12-05" | 5 Dec 111 BC  |-  | data-sort-value="-35-01-07" | 7 Jan 35 BC  |-  | data-sort-value="-207-12-05" | 5 Dec 207 BC  |}  

Any format can be used for what is seen by readers:

src: s-media-cache-ak0.pinimg.com

Examples of datatype auto detection

The script sees what the cells contains at the first 5 data rows. The sorting mode becomes numeric if the first cells contains a number only (comma and full-stop used in number formatting are accepted as number). The sorting order will work properly even though other cells contains text after numbers (e.g. "80 approx"). Empty cell is treated as "zero" when sorting numerically.

The example with "a" gives alphabetic sorting; that with "e" ditto, the data are not mistaken for numbers in scientific format.

The first example demonstrates that text is positioned at zero, and that e.g. e3 for 1000 is not allowed; use 1e3 instead. It also shows that "-" should be used, not "-".

The second example shows that expressions are not sorted according to their evaluated value, but according to the first number.

The third example shows that a percentage is accepted for numeric sorting mode, but ignored in the actual sorting, so if a column contains percentages, all numbers have to be written as a percentage.

The fourth example shows again that "c. 12" sorts at 0, as opposed to 12 with some text after it, which sorts at 12. In case such an element arrives at the top of a column, it causes alphabetic sorting mode.

src: c8.alamy.com

Background colors in sortable headers

A background color in a header may cause that column to lose its sorting button - see bug 31755. Example:

style="background:...;" causes the problem.

Use style="background-color:...;" to make the color show. Correct method:

Produces this sortable table:

src: i.ytimg.com

Tips and tricks

Excluding rows from sorting

Sometimes it is helpful to exclude the last row of a table from the sorting process. There are two methods to achieve this.

Header as a footer

You want a repeat of the header at the bottom. You do this by using the ! (Exclamation mark) syntax for all cells in the last row of the table. This will be recognized as a footer and the row will not be part of the sorting.

Wiki markup

  {|class="wikitable sortable"  !Name!!Surname!!Height  |-  |John||Smith||1.85  |-  |Ron||Ray||1.89  |-  |Mario||Bianchi||1.72  |-  !Name!!Surname!!Height  |}  

What it looks like in your browser

This applies to all rows at the end of the table that are consecutive and fully made up out of header cells.

Plain footer

This can be achieved using class="sortbottom" on the desired table row (line starting with |-).

Wiki markup

  {|class="wikitable sortable"  !Name!!Surname!!Height  |-  |John||Smith||1.85  |-  |Ron||Ray||1.89  |-  |Mario||Bianchi||1.72  |- class="sortbottom"  |colspan="2" | Average:||1.82  |}  

What it looks like in your browser

It is possible to keep multiple lines fixed at the bottom, as long as the lines are consecutive.

Forcing proper sort type and positioning rows with a hidden sort key

One way to ensure each row is sorted appropriately is to add identical hidden rows ( |-style="display:none;" ) to the top and bottom of the table. If these contain very high and very low values of the appropriate type for sorting each column, then no matter what sorting is done, one of the rows always remains at the top and one at the bottom of the table, forcing the appropriate mode for the next sort. If it is acceptable to keep identical rows fixed at the top and the bottom of a table, these can be implemented using less extreme high and low hidden sort key values. The hidden rows to force proper sort type may be unnecessary if the rows for display at the top and bottom of the table contain the right sort of values. For example, the hidden top and bottom rows in the example below can be deleted without harm, but if "(meters)" were added in the third column they would be needed.

Since the numeric sorting recognizes scientific notation, the number 9e99 and its negative are good candidates for forced numeric sorting when dealing with tables that contain large numbers. On the other hand, characters are ranked "ASCIIbetically", which places the exclamation mark (!) as the first sortable character and the tilde key (~) as the last; as such those two characters are good candidates for alphabetical sorting.

Sorting with a hidden key

You can customize the sorting on a table by placing a value that is easily sorted before the content, and then hiding that value with HTML/CSS. To do this, enclose the value you wish to hide in <span class=sortkey> and </span>, or <span style="display: none;"> and </span>, or use the template {{Hs}}. For example, this technique can be used to create a sortable table containing the months:

Javascript sorting sorts the text inside and outside the tags, without the tags themselves. A hidden key can be put at the start. Both in the case of alphabetic and that of numeric sorting the first parts determine the order. Both parts together are used to determine the sort mode, so for numeric sorting the whole should be a valid number.

Alphabetic sorting with hidden key

The key comes at the start and is separated from the displayed text in such a way that the latter does not affect the sorting order. For example, if there are no blank spaces in any key, then a blank space can be used for separation. If a single blank space is possible in a key, two   can be used. For table elements for which the text to be displayed is equal to the key, no duplication is needed, of course.

If the text inside and outside the tags together is of a form that would cause a sorting mode other than alphabetic (if and when the element is at the top), a character can be appended at the end of the key to avoid this, again making sure it does not affect the sorting order by putting a space or two  . This can be dispensed with if the element can never be at the top, but this can be complicated to assess as that can be caused by sorting other columns, with varying sorting modes, and it can change when deleting a row, adding a column, etc.

Instead of "display=none" another way is using a font color equal to the background, e.g. {{font color}} gives "". With this method the hidden code can be seen in selected text (e.g. with the mouse). Also the hidden text is included when copying the rendered text. The first may be an advantage or a disadvantage, the second seems only a disadvantage. A complication is also that if a user uses a background color different from the default, the specified text color may not match it; to make sure they are the same the background color can be specified also.

Numeric sorting with hidden key

If one needs to use alphabetic sort mode for numbers, one can construct a hidden alphabetic key for this purpose. The simple way of achieving this is to use template {{nts}} or {{ntsh}}.

It can also be done manually for all numbers between -1e100 and 1e100 in arbitrary precision as follows:

• where scientific notation is used, it is normalized such that the absolute value of the mantissa is between 1 and 10; the exponent is put first
• scientific notation is used for all negative numbers, and all positive numbers outside some interval (below: 1e-9 to 1e9), and not inside that interval
• where the absolute value of the exponent and/or the mantissa is a decreasing function of the number, the notation uses its complement with respect to 99 for exponents and 10 for mantissas; the code "c" is added in these cases
• numbers 0 <= x < 1000 get a "+" in front
• positive numbers in scientific notation with a negative exponent get "+0" in front
• spaces inside the code and &-signs in front are added where needed:
  • for numbers not in scientific notation the positions of all explicit and implicit decimal points are aligned
  • for the starting position, i.e. the position of the first "-", "+", or "e", of other numbers, see the example table
  • no code should satisfy the criterion for numeric sorting mode (below we have always either an ampersand or two letters e): although this matters only for the element at the top, any element might arrive at the top due to sorting another column

In the following the left column shows the code for alphabetic sorting, where cryptic followed by the regular notation. The second column contains the same (hence sorting the same), but with code hidden with CSS. The third column does not contain hidden parts and uses numeric sort mode. When sorting the first or second column "more than 1e9" is positioned suitably, while when sorting the third column it is positioned like 0. Moreover, if this cell would be at the top alphabetic sort mode would be used.

Padding

Sometimes entries are padded on the left for alignment purposes. This can adversely affect how they are sorted.

Non-breaking spaces

The effect of left-padding with non-breaking space codes   which render as blank spaces, depends on the browser: in IE they are (unlike actual blank spaces) counted for sorting as leading blank spaces, so in a list of numbers with text (for which the alphabetic sorting mode applies) they could be used to equalize the number of characters before the explicit or implicit decimal separator. However, in Firefox they are ignored for the purpose of sorting.

See also Talk:List of U.S. states and territories by population/Archive 1#Sortable Table.

Padding with zeros

Example:

• 000156

Formatnum can be combined with padleft:

Integer:

{{formatnum:{{padleft:299792458|16|0}}}} gives:

• 0,000,000,299,792,458

Real:

{{formatnum:{{padleft:{{#expr:((299792458.056 - .5) round 0)}}|16|0}}}}.{{padleft:{{#expr:(1000000*(299792458.056 - ((299792458.056 - .5) round 0))) round 0}}|6|0}} gives:

• 0,000,000,299,792,458.056000

Dates

The simplest way to format sortable dates in a table is to use the {{dts}} template. In accordance with the manual of style, the template would be invoked using the following format:

• {{dts|4 July 1776}}

Please see the documentation of the template {{dts}} for full details on how to use this.

Issues

Date sorting works by formatting dates so they can be sorted numerically. For example:

• yyyy mm dd

or

• 2001 07 21

...for 21 July 2001. The "display:none" style can be used to hide a sortable numeric date before the displayed date. {{dts}} does this automatically, and is recommended in most cases.

You can use July 7, 2012 etc. to get sortable dates. Example:

For years BC, !9937-09-23 can be used for -0062-09-23 (62 BC): Simply subtract the year BC from 10,000.

• See also: bugzilla:8226

Numeric sort for BC/AD years

In certain circumstances the following sort technique may be used to provide a simple intuitive numeric sort for BC/AD years which are often surrounded by qualifying text. The sort in the BC/AD column (the fourth column in the example) is forced to be numeric (just as the other columns are forced to be alphabetic) by the inclusion of the first two hidden rows. These rows contain extreme values which will mean that these rows will ALWAYS be sorted to the top and bottom of the table, regardless of which column is sorted. As the sort mechanism determines the sort type to be used by examining the first cell in the column to be sorted the hidden rows ensure that a purely numeric value is always found in the first or last cell.

The mechanisms used here are explained in the current article at: #Forcing proper sort type and positioning rows with a hidden sort key and #Examples.

With numeric sorting guaranteed all that is needed is to precede the BC/AD text with a positive or negative year number in a hidden sort key ( {{Hs|-9999 ! }} ) which suitably represents the cell text. As this number will be the first thing the sort code sees it will sort it as a number, in the order large negatives -> zero -> large positives, or the opposite. Once the sort type is fixed at the start of a sort the presence of alphabetic values in subsequent rows is ignored. The sort is done numerically on the first text in each row. The detail of the exclamation mark after the positive/negative year number in the hidden sort key is to clearly mark an end to the number which the sort mechanism must consider. In certain circumstance, if the exclamation mark is not present, and the hidden sort key is immediately followed by another number, that number may be treated as a continuation of the hidden sort key number, to produce an incorrect sort.

The tables in the article: List of cities by time of continuous habitation have been modified to used this sort. The following example is modified (maintaining some defects in the content which will need resolving in the original!) from one of those tables:

  {| class="wikitable sortable"  |-  ! Name  ! Historical region  ! Location  ! Continuously inhabited since  ! class="unsortable" | Notes    <!-- force numeric sorting on the hidden values in col 4 with hidden extreme max and min rows -->  |-style="display:none;"  |!a||!a||!a||-9e99    |-style="display:none;"  |~z||~z||~z||9e99    |-  | [[Ife]] || || {{Hs|Nig}}[[Osun State]], [[Nigeria]] || {{Hs|-500 !}}c. 500 BC ||    |-  | [[Axum]] || [[Kingdom of Axum]] || [[Ethiopia]] || {{Hs|-400 !}}c. 400 BC || Ancient capital of the Kingdom of Axum  .  .  .  |-  | [[Mogadishu]] || || [[Somalia]] || {{Hs|900 !}}c. 900 || settled by Arab traders    |-  | [[Dar es Salaam]] || || [[Tanzania]] || {{Hs|1865 !}}1865 || Founded by the Sultan of [[Zanzibar]].    |}  

Controlling sorting and display

Text undesired for sorting but needed for display:

• In numeric sorting mode, text breaks numerical sorting whether the text is before or after the number. Sorting then becomes alphanumeric. Empty cell is treated as "zero" when sorting numerically.
• In date sorting mode, this text needs to be put in a separate column; in the case of a cell containing a range of dates or numbers (e.g. from .. to ..), text in surplus of what is required for sorting is put in the extra column. If the first part of the text is used for sorting, then the extra column needs to be the following one; conversely, if the last part of the text is used for sorting, then the extra column needs to be the previous one; depending on the table format, this dividing of an item over two cells may look ugly.
• In alphabetic sorting, any footnotes etc. do not require a separate column; they can simply be put at the end of the element.

Text undesired for display but needed for sorting:

• can be put as hidden text in the column to be sorted

Combining the two, we can have displayed text independent of text used for sorting, by fully hiding the latter, and fully putting the former in a separate column (in date sorting mode and numeric sorting mode) or in the same column after the hidden text (in alphabetic sorting). Fully putting the displayed text in a separate column may look ugly if it is not done consistently for a whole column, but only for elements that require this (e.g. if most entries in a column are single numbers, but some are ranges).

Static column

A static column, e.g. with row numbers, can be obtained with two side-by-side tables with for each row the same height set in both tables:

The style can be adjusted to make it appear as a single table. If for some row the height of that row is too small for the text in a cell on one of the sides, the browser increases it, and there is no longer a match.

A static column can also be created by enclosing the sortable table with the templates {{static column begin}} and {{end}}. See the documentation of {{static column begin}} for details.

Maintaining tables sorted by rank

Tables in rank order may become difficult to maintain as the list is updated. People keep adding more rows to the table, but fail to renumber all the ranks each time a new one is added, because it seems too laborious.

One way to resort a table that has been updated is to copy the table (in wiki markup), remove the table code ("|-", etc.), replace the cell separation code ("||") with Tab characters using Notepad (included with Windows) or TextEdit (included with OS X) and paste the table data into Excel or Google Docs (free of charge). Type "1" and "2" in the first two rows of the rank column, select both cells and then fill out the rest by dragging down the little blue square on the lower-right corner of the second cell. Copy the table from the spreadsheet and paste it into a text editor. Finally, add back the wiki table code with the text editor.

Putting a table in initial alphabetical order

Decide which column to use to alphabetize the table. Also, decide where you want the column. The first column is usually best. Columns can easily be moved with the VisualEditor. Click on a cell in that column. Then click on the arrow that shows up at the top of the column. Then click on "move before" or "move after" as needed.

Once your columns are set up, then you can move the rows around in order to alphabetize them. Unfortunately, the VisualEditor does not have a way to quickly alphabetize a table. Click on a cell in a row. Then click on the arrow that shows up at the left of the row. Then click on "move above" or "move below" as needed.

If this is buggy or not working, the rows can be moved around in the wikitext by cutting and pasting rows in the wikitext. Either method of moving rows around in order to alphabetize them (wikitext editing or VisualEditor editing) can be time-consuming for long tables. For long tables there is a quicker way explained below.

A way to do that is to launch freeware LibreOffice Calc. Go to the wikipedia page or sandbox with the table. Select and copy the table right off the page (do not go into the wikitext or the HTML). Paste it into a new Calc page. In Calc click on any cell in the column you want alphabetized, and then click on one of the sort options (ascending or descending) in the data menu at the top of the Calc window. Then convert the Calc table back to wikitext by pasting it into tab2wiki. For more info see Commons:Convert tables and charts to wiki code or image files.

There is another way to alphabetize a table. One can use NoteTab Light (freeware version of NoteTab). It installs quickly and easily. But the wikitext must be in compressed table format. All the wikitext for a row must be on one line. That means the cells in that row are separated by double bars ||.

To alphabetize the list by the first column paste the table wikitext into a new NoteTab Light page. Select the rows you want to alphabetize. Then click on the "modify" menu, then "lines", then "sort", and then "ascending". That will put "A" at the top and "Z" at the bottom.

Then put back |- (wikitext for row) between each line. Do that via find-and-replace by replacing ^p with ^p|-^p

^p is the underlying text editor code for line breaks in NoteTab.

|- is the wikitext for a table row.

If there are blank lines between the entries replace ^p^p with ^p|-^p

Copy the wikitext and paste it back into the article. Save the page.

Initial alphabetical sort versus initial sort by rank order

It is a good idea to keep lists and tables in some kind of initial non-random sort order. Numbered rank order can be difficult to maintain as the list is updated, and as the rankings change. For example; in a nation list, updating the info for a single nation may require changing the rank numbers of many nations.

This discourages people from updating the list. If they do update the list, they may not bother to update the rank order. So the list becomes more and more incorrect over time. See lists of country data. See Category:Lists of countries by per capita values and Category:Lists of countries.

It can be even easier maintenance and updating in some cases if the list is initially in alphabetical order, especially if the sources and references are also in alphabetical order. Readers can be instructed to use the sort button to order a number column.

Removing a rank column (1,2,3) from a table

You can remove the rank column cells quickly. It is much easier now with the table editor in the VisualEditor. Click on a cell in the column you want to delete. An arrow will show up at the top of the column. Click the arrow, and then "delete column".

Auto-ranking or adding a row numbering column (1,2,3) next to a table

There are Phabricator threads asking for a table option for a fixed column, a static rank-order column, or row numbering. See phab:T42618. It supercedes phab:T42634. A patch is being tested now. When the patch is implemented in Wikipedia it will be possible to use references, flag icons, italics, and wide note columns in tables with autonumbering of rows.

The rank column (1,2,3) can be removed, and put to the side of the table as a row numbering column. See examples farther down. See List of countries by incarceration rate. Its editing is explained in detail at Commons:Convert tables and charts to wiki code or image files (section about list of countries by incarceration rate). See also: List of countries by total health expenditure per capita. Be careful if you want to use flag icons with the country names. Sometimes they mess up row alignment more and more as the text size used is smaller and smaller. The row alignment is more and more messed up the farther down one scrolls down the table. At the time this is written the flag icons are formatted in such a way that they are not causing a problem. For example; see: List of countries by intentional homicide rate.

The row number column never has to be updated, except to add more numbers at the end if necessary. For example; when adding more nations. This allows any initial sort order for the table. It allows any column to be sorted later via the sort button, and still see the same row numbering.

In the examples below click the sort button above a column in the main table to the right of the row number column. Note that the row number column on the left does not change. It sorts independently. This allows one to see rank order for any column. The row number column does not have to sort at all. It depends on the table needs and setup. A note can be added above the table; something like this:

A separate row number column only works when there is only one line per row in the main table. So wide tables, or tables with a notes column are problematic. There could be 2 lines in some rows, depending on screen width, and the length of notes. Rows will wrap from being one line to two lines. Decrease your browser width to see. For example; see notes column here: List of countries and dependencies by area. Wide tables can be narrowed in some cases by using breaks in the header titles: <br>. Also, the sorting icons can be put in a separate header row.

Tables with references within the table are problematic. Reference numbers are in superscript, and this may or may not increase the line height of the row. It usually does. It depends on the current state of the MediaWiki software, and whether it increases line height for rows with references. So a separate row number column may not work in this case, especially when multiple cells in a column have references. The more rows with references, the more the misalignment as one goes down the table. One solution is to point to a notes section below the table. See: List of countries by intentional homicide rate. The references are above the table, or in the notes section below the table.

Italics within the table are also problematic. It depends on the current state of the MediaWiki software, and whether it changes the line height for rows with italics.

Example tables

Here is how to put a main table adjacent to a separate row number table.

The two tables are combined by wrapping them within a 3rd table that does not have a border. Look at the wikitext to understand. See examples below. It is not necessary to put text in the header cell above the number column. You can leave it blank, but sortable. Add <br> so it is not too narrow. You can also choose to leave the number column unsortable. Specify class="unsortable" in the attributes of its header cell. For more info see the section higher up called Making a column unsortable.

Align the multiple headers across the tables below by adding <br> (multiple times if necessary) to the header cells of the rank column. See the wikitext for the table below. See also: List of U.S. states by incarceration and correctional supervision rate and List of countries by intentional homicide rate#By country. Those tables have several header rows.

You can remove the space between the 2 tables by adding style="margin-right: -8px;" to the top line of the wikitext of the row number table. It may not be a good idea to do this though in many cases. Fixed row numbering is more intuitive when there is a space between tables. Otherwise people may not understand why the numbers are not sorting along with the rest of the table.

{| class="wikitable sortable" style="margin-right: -8px;"

With wider tables the rows only line up between the table and the rank column if all the rows below the headers only use one line each. So it is a good idea to avoid tables that are too wide. For that reason avoid note columns, too. Narrow your browser window to see the problem with wider tables such as the one below. Another problem is that the rank column can drop down out of sight when the tables are viewed on a narrow screen, or when the browser width is narrowed.

Adding style="vertical-align:top;" will keep the tops aligned between the 2 tables at all browser widths. The rank column will not drop down.

For the above table here is the wikitext at the top of the wrapping table, followed by the header wikitext for the rank column:

  {|  |- style="vertical-align:top;"  |  {| class="wikitable sortable"  |-  ! <br>  |-  ! <br><br>  |-  ! <br>  |-  | 1  

Sorting the wikitext of a table

One difficult way to sort the wikitext itself by a certain column is to use the following 'trick'. You can make an auxiliary sortable table containing the wikitext for the original table, and sort it. You can then replace the original wikitext by this sorted wikitext.

Unfortunately this method is anything but quick and easy. The heavy modifications needed make it unsuitable for larger tables, while small tables generally are sorted faster by hand.

Example:

Original table:

Auxiliary table:

  {|class="wikitable sortable"  !demo  {|class="wikitable sortable"  !header  |-  ||-  | 9  |-  ||-  |12  |-  ||-  |11  |}  |}  

Now you can sort the above table, and copy the rendered text to the edit box. After deleting the "header" line, this renders as a new defaultly sorted table:

Alphabetic sorting order

Sort the following table to see an example of the alphabetic sort order. Note that sorting is case-insensitive: the two-character entries such as A1 demonstrate that A and a are at the same position.

Sorting with increase/decrease/steady templates

To enable sorting of cells with Template:Increase, Template:Decrease or Template:Steady, add a sort key, e.g. {{increase|2}}2, {{decrease|-1}}1 or {{steady|0}}. To fix an existing table, use Search and replace (right icon in the Advanced toolbar) with Treat search string as a regular expression selected to do the following replacements:

src: answers.unrealengine.com

See also

• {{Sortname}} - Sort by surname without placing first name and surname in two separate columns
• m:Help:Sorting - The general help page of this functionality (Not Wikipedia specific)
• Sortable collapsible table
• Template:dts (backlinks edit) - sorting a table by a date column, while following w:Wikipedia:Manual of Style (dates and numbers)#Dates containing a month and a day for display
• Category:Sorting templates - All templates that provide functionality related to sorting.
• How to put zebra stripes on sortable wiki tables

Source of the article : Wikipedia