Module:String: Difference between revisions

end

--[====[

pos

This function returns a single character from the target string at position pos.

Usage:

{{#invoke:String|pos|target_string|index_value}}

OR

{{#invoke:String|pos|target=target_string|pos=index_value}}

Parameters

target: The string to search

pos: The index for the character to return

If invoked using named parameters, Mediawiki will automatically remove any leading or

trailing whitespace from the target string. In some circumstances this is desirable, in

other cases one may want to preserve the whitespace.

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards

from the end of the string. In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.

]====]

function str.pos( frame )

local new_args = str._getParameters( frame.args, {'target', 'pos'} );

local target_str = new_args['target'] or '';

local pos = tonumber( new_args['pos'] ) or 0;

if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then

return '<strong class="error">String index out of range</strong>';

end

return mw.ustring.sub( target_str, pos, pos );

if target_str == '' then