PHP | ctype_upper() Function

Last Updated : 04 Jun, 2018

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";
    }
?>

Output:

Yes

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";
    }
}

?>

Output:

Yes
No
No
Yes

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";
    }
}

?>