The ctype_lower() function is an inbuilt function in PHP which is used to check whether the given characters in the string is lower case or not.
Syntax:
bool ctype_lower( string $text )
Parameters: This function accepts single parameter $text which holds the string that need to be tested.
Return Value: This function returns TRUE if all characters of a string is a lowercase character in the current locale.
Below programs illustrate the ctype_lower() function in PHP:
Program 1:
<?php   // PHP program to check the string contains // all lower case characters or not $strings = array('gfg123', 'neveropen', 'GfG');   // Loop to check the above three strings foreach ($strings as $testcase) {     if (ctype_lower($testcase)) {         echo "Yes\n";     } else {         echo "No\n";     } } ?> |
Output:
No Yes No
Program 2:
<?php   // Declare a string $str = "neveropen";   $n = strlen($str);   $count = 0;   for($i = 0; $i < $n; $i++) {     if(ctype_lower($str[$i])) {         $count++;     } }   echo "Totla number of lower case "     . "character in string: "     . $count; ?> |
Output:
Totla number of lower case character in string: 11
Reference: https://www.php.net/manual/en/function.ctype-lower.php
