PHP | ctype_upper() Function

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 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 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 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";
    }
}

?>

Output:

No

References : http://php.net/manual/en/function.ctype-upper.php