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
