ctype_lower(): Checking for all lower case letters
ctype_upper($input_string);
Checking for presence of only lower case letters by using ctype_lower()
Return value will be TRUE ( if all lower case chars ) or FALSE.
Here is the code using ctype_lower()
$string='abcasdf';
if (ctype_lower($string)) {
echo " All characters are Lower case only ";
}else{
echo " All characters are not lower case ";
}
The output of above code will be
All characters are Lower 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.
$string='abc asdf';
if (ctype_lower($string)) {
echo " All characters are Lower case only ";
}else{
echo " Not all characters are lower case ";
}
Output will be
Not all characters are lower 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)asdf';
Output will be
Not all characters are lower case
Examples multiple strings & ctype_lower()
$str = array("hello world", "abcdef", "ab#cd","34",442);
foreach ($str as $val){
if (ctype_lower($val)){
echo "<p class='text-success'>The string <b>$val</b> consists of lower Case letters .</p>";
} else {
echo "<p class='text-danger'>The string <b>$val</b> does not consist of all lower case letters.</p>";
}
}
The string hello world does not consist of all lower case letters.
The string abcdef consists of lower Case letters .
The string ab#cd does not consist of all lower case letters.
The string 34 does not consist of all lower case letters.
The string 442 does not consist of all lower case letters.
