ctype_upper():Checking for all upper case by using ctype_upper()
ctype_upper($input_string);
Checking for presence of only upper case letters by using ctype_upper()
We can check a string to know if all characters present are in upper case letters or not.
Return value will be TRUE ( if all are Upper case chars ) or FALSE.
Here is the code using ctype_upper()
$string='ABCDEF';
if (ctype_upper($string)) {
echo " All characters are Upper case only ";
}else{
echo " All or some characters are NOT Upper case ";
}
The output of above code will be
All characters are Upper case only
Presence of Blank space
This function checks for lower cases chars only so presence of any blank space will return as FALSE only.
$string='ABC DEF';
if (ctype_lower($string)) {
echo " All characters are Upper case only ";
}else{
echo "All or some characters are NOT Upper case ";
}
Output will be
All or some characters are NOT Upper case
Presence of Special characters
Presence of Special characters will also return FALSE , only change the string part like this in above code.
$string='ABC)DEF';
Output will be
All or some characters are NOT Upper case
Examples multiple strings & ctype_upper()
$str = array("HELLO WORLD", "ABCDEF", "AB!CD","67");
foreach ($str as $val){
if (ctype_upper($val)){
echo "<p class='text-success'>The string $val consists of Upper Case letters .</p>";
} else {
echo "<p class='text-danger'>The string $val does not consist of all Upper case letters.</p>";
}
}
Output is here
The string HELLO WORLD does not consist of all Upper case letters.
The string ABCDEF consists of Upper Case letters .
The string AB!CD does not consist of all Upper case letters.
The string 67 does not consist of all Upper case letters.
