[Solved] How to check, if a php string contains only english letters and digits?

In JS I used this code:


but I don’t know, how to do it in PHP.

Solution #1:

Use preg_match().

if (!preg_match('/[^A-Za-z0-9]/', $string)) // '/[^a-zd]/i' should also work.
  // string contains only english letters & digits
Respondent: Frosty Z

Solution #2:

if(ctype_alnum($string)) {
    echo "String contains only letters and numbers.";
else {
    echo "String doesn't contain only letters and numbers.";
Respondent: vineeth

Solution #3:

You can use preg_match() function for example.

if (preg_match('/[^A-Za-z0-9]+/', $str))
  // ok...
Respondent: evilone

Solution #4:

if you need to check if it is English or not. you could use below function. might help someone..

function is_english($str)
    if (strlen($str) != strlen(utf8_decode($str))) {
        return false;
    } else {
        return true;
Respondent: shakee93

Solution #5:

Have a look at this shortcut

if(!preg_match('/[^W_ ] /',$string)) {


the class [^W_] matches any letter or digit but not underscore . And note the ! symbol . It will save you from scanning entire user input .

Respondent: HalfWebDev

Solution #6:

if(preg_match('/[^A-Za-z0-9]+/', $str)) {
    // ...
Respondent: Vitamin

Solution #7:

if (preg_match('/^[ws?]+$/si', $string)) {
    // input text is just English or Numeric or space
Respondent: Ramin Rabiee

Solution #8:

if(preg_match('/^[A-Za-z0-9]+$/i', $string)){ // '/^[A-Z-a-zd]+$/i' should work also
// $string constains both string and integer

The carrot was in the wrong place so it would have search for everything but what is inside the square brackets. When the carrot is outside it searches for what is in the square brackets.

Respondent: user3439891

Solution #9:

PHP can compare a string to a regular expression using preg_match(regex, string) like this:

if (!preg_match('/[^A-Za-z0-9]+/', $string)) {
    // $string contains only English letters and digits
Respondent: Saurabh

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