(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
ctype_lower — Check for lowercase character(s)
Checks if all of the characters in the provided string,
text, are lowercase letters.
textThe tested string.
Note:
If an int between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.
Returns true if every character in text is
a lowercase letter in the current locale.
When called with an empty string the result will always be false.
Example #1 A ctype_lower() example (using the default locale)
<?php
$strings = array('aac123', 'qiutoas', 'QASsdks');
foreach ($strings as $testcase) {
if (ctype_lower($testcase)) {
echo "The string $testcase consists of all lowercase letters.\n";
} else {
echo "The string $testcase does not consist of all lowercase letters.\n";
}
}
?>The above example will output:
The string aac123 does not consist of all lowercase letters. The string qiutoas consists of all lowercase letters. The string QASsdks does not consist of all lowercase letters.