PHP | ctype_upper() Function

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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"; 
    } 
} 
  
?> 