ctype_lower(): Checking for all lower case letters
Check whether all characters are lowercase or uppercase
Use ctype_lower() or ctype_upper() with string input when every character must satisfy the selected case test. An empty string returns false, and non-string arguments should not be used as character-code shortcuts in current PHP.
$lower = 'php';
$upper = 'PHP';
var_dump(ctype_lower($lower)); // true
var_dump(ctype_upper($upper)); // trueStart with this current pattern. The examples below are retained, corrected where necessary, and expanded for additional variations and output.
$string='abcasdf';
if (ctype_lower($string)) {
echo " All characters are Lower case only ";
}else{
echo " All characters are not lower case ";
}
All characters are Lower case onlyctype_upper($input_string);Return value will be TRUE ( if all lower case chars ) or FALSE.
Presence of Blank space
This function checks for lower cases chars only so presence of any blank space will return as FALSE only.$string='abc asdf';
if (ctype_lower($string)) {
echo " All characters are Lower case only ";
}else{
echo " Not all characters are lower case ";
}
Not all characters are lower casePresence of Special characters
Presence of Special characters will also return FALSE , only change the string part like this in above code.$string='abc)asdf';Not all characters are lower caseExamples 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.
String Functions Check for Upper case chars only ucwords(): To Change first char of all words to upper case of a string. how to change all the letters to upper case Converting string to all lower case letters
Subhendu Mohapatra
Author & Instructor at plus2net
I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.
Subscribe to our YouTube Channel here
