PHP | ctype_upper() Function
Last Updated :
11 Jul, 2025
The ctype_upper() function in PHP used to check each and every character of a given string is in uppercase or not. If the string in upper case then it returns TRUE otherwise returns False.
Syntax:
ctype_upper (string text)
Parameter Used:-
- $text : The tested string.
Return Value:
Function returns True if each character of text in Upper Case or False if text is not in upper case.
Examples:
Input : GEEKSFORGEEKS
Output : Yes
Explanation: All characters of "GEEKSFORGEEKS"
in UPPERCASE.
Input : GFG2018
Output : No
Explanation : In text "GFG2018", '2', '0', '1', '8'
are not in UPPERCASE.
Input : GFG INDIA
Output : No
Explanation : In String "GFG INDIA" a special character [space]
between GFG and INDIA. so answer will be No.
Note: Except string, if we input anything then it will return FALSE.
Below program illustrates the ctype_upper() function in PHP:
Program: 1
php
<?php
// PHP program to check given string is
// all characters -Uppercase characters
$string1 = 'GEEKSFORGEEKS';
if (ctype_upper($string1)) {
// if true then return Yes
echo "Yes\n";
} else {
// if False then return No
echo "No\n";
}
?>
Program: 2 passing array of string as text and print result for individual values.
PHP
<?php
// PHP program to check given string is
// all characters -Uppercase characters
$strings = array('GEEKSFORGEEKS', 'First',
'PROGRAMAT2018', 'ARTICLE');
// Checking above given four strings
//by used of ctype_upper() function .
foreach ($strings as $test) {
if (ctype_upper($test)) {
// if true then return Yes
echo "Yes\n";
} else {
// if False then return No
echo "No\n";
}
}
?>
Program: 3 Drive a code
ctype_upper() function where input will be space, special symbol, returns False.
PHP
<?php
// PHP program to check given string is
// all characters -Uppercase characters
$strings = array('GEEK @ . com');
// Checking above given four strings
//by used of ctype_upper() function .
foreach ($strings as $test) {
if (ctype_upper($test)) {
// if true then return Yes
echo "Yes\n";
} else {
// if False then return No
echo "No\n";
}
}
?>
References :
https://www.php.net/manual/en/function.ctype-upper.php
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