PHP | IntlChar::islower() Function
Last Updated :
11 Jul, 2025
The IntlChar::islower() function is an inbuilt function in PHP which is used to check whether the given input character is a lowercase character or not.
Syntax:
bool IntlChar::islower( $codepoint )
Parameter: This function accepts a single parameter $codepoint which is mandatory. The input parameter is a character, which is encoded as a UTF-8 string.
Return Value: If $codepoint is a lowercase character then it returns True, otherwise return False.
Below programs illustrate the IntlChar::islower() function in PHP:
Program 1:
PHP
<?php
// PHP code to illustrate IntlChar::islower()
// function
// Input data is character type
var_dump(IntlChar::islower("a"));
var_dump(IntlChar::islower("A"));
var_dump(IntlChar::islower("\u{0041}"));
// Input data is control character
var_dump(IntlChar::islower("\t"));
// Input data is string type
var_dump(IntlChar::islower("Geeksforgeeks"));
// Input data is number type
var_dump(IntlChar::islower("2018"));
// Input data is single digit
var_dump(IntlChar::islower("5"));
?>
Output:
bool(true)
bool(false)
bool(false)
bool(false)
NULL
NULL
bool(false)
Note: If String and Numbers (except single digit number) are used as a parameter then it returns NULL.
Program 2:
PHP
<?php
// PHP code to illustrate IntlChar::islower()
// Declare an array $arr
$arr = array("a", "\u{FF41}", "A", "\u{0041}", "0", "\n", "123", "Geeks");
// \u{0041} is ASCII value of 'A'
// \u{FF41} is ASCII value of 'a'
// Loop run for every array element
foreach ($arr as $val){
// Check each element as code point data
var_dump(IntlChar::islower($val));
}
?>
Output:
bool(true)
bool(true)
bool(false)
bool(false)
bool(false)
bool(false)
NULL
NULL
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Reference: https://www.php.net/manual/en/intlchar.islower.php