JavaScript: check if a giving string contains only letters or digits

Question

Using JavaScript, I wanna check if a giving string contains only letters or digits and not a special characters:

I find this code which checks if a string contains only letters:

    boolean onlyLetters(String str) {
      return str.match("^[a-zA-Z]+$");
    }

but my string can contain digits too. can you help me?

thanks in advance :)

bugwheels94 · Accepted Answer · 2019-10-03T07:32:30.417

23

Add 0-9 also to your regex

 boolean onlyLetters(String str) {
   return str.match("^[A-Za-z0-9]+$");
 }

edited Oct 03 '19 at 07:32

answered Sep 08 '14 at 14:10

bugwheels94

str.match instead of str.matches would be better – Vaidas May 10 '19 at 23:07
1

This also return not null value for `onlyLetters("ser[]ver")` – Dandelion Oct 02 '19 at 10:43
1

@Dandelion Fixed. The previous answer was plain wrong – bugwheels94 Oct 03 '19 at 07:32

score 8 · Answer 2 · answered Sep 08 '14 at 14:11

8

Using regexp, you can add 0-9 to say any digit between 0 and 9:

boolean onlyLettersAndDigits(String str) {
      return str.matches("^[a-zA-Z0-9]+$");
    }

answered Sep 08 '14 at 14:11

valjeanval42

2 Answers2