PHP | IntlChar foldCase() Function

The IntlChar::foldCase() function is an inbuilt function in PHP which is used to perform case folding on a code point. Case folding means the given character is mapped to its equivalent lowercase characters.
Syntax:

mixed IntlChar::foldCase( $codepoint, $options = 
IntlChar::FOLD_CASE_DEFAULT )

Parameters: This function accepts two parameters as mentioned above and described below: 

• $codepoint: This parameter is a character or integer value, which is encoded as a UTF-8 string.
• $options: This parameter holds the character constants IntlChar::FOLD_CASE_DEFAULT by default or IntlChar::FOLD_CASE_EXCLUDE_SPECIAL_I.

Return Value: This function returns Simple_Case_Folding of the codepoint. If the codepoint has no case folding equivalent, then the codepoint itself is returned.
Below program illustrates the IntlChar::foldCase() function in PHP:
Program:

php

<?php
// PHP program to illustrate the IntlChar::foldCase() function

var_dump(IntlChar::foldCase('AA', IntlChar::FOLD_CASE_EXCLUDE_SPECIAL_I));

var_dump(IntlChar::foldCase('@', IntlChar::FOLD_CASE_EXCLUDE_SPECIAL_I));

var_dump(IntlChar::foldCase('&', IntlChar::FOLD_CASE_EXCLUDE_SPECIAL_I));

var_dump(IntlChar::foldCase('C', IntlChar::FOLD_CASE_DEFAULT));

var_dump(IntlChar::foldCase('Lt', IntlChar::FOLD_CASE_DEFAULT));

var_dump(IntlChar::foldCase('/', IntlChar::FOLD_CASE_DEFAULT));

var_dump(IntlChar::foldCase('g', IntlChar::FOLD_CASE_DEFAULT));

var_dump(IntlChar::foldCase('1', IntlChar::FOLD_CASE_DEFAULT));

?>

Output:

NULL
string(1) "@"
string(1) "&"
string(1) "c"
NULL
string(1) "/"
string(1) "g"
string(1) "1"

Reference: https://www.php.net/manual/en/intlchar.foldcase.php