javascript - Regex: Capturing all digits in a string, and returning as a new string of digits - Stack Overflow

I am trying to capture all the digits of an input string. The string can also contain other characters like letters so I can't simply do [0-9]+.

I've tried /[0-9]/g but this returns all digits as an array.

How do you capture, or match, every instance of a digit and return as a string?

I am trying to capture all the digits of an input string. The string can also contain other characters like letters so I can't simply do [0-9]+.

I've tried /[0-9]/g but this returns all digits as an array.

How do you capture, or match, every instance of a digit and return as a string?

• javascript
• regex

Share Improve this question Follow edited Feb 15, 2013 at 20:01 Rohit Jain 213k4545 gold badges414414 silver badges533533 bronze badges asked Feb 15, 2013 at 19:52 CodyBugsteinCodyBugstein 23.4k6767 gold badges225225 silver badges381381 bronze badges 2

• What language are you using? – Rohit Jain Commented Feb 15, 2013 at 19:53
• JavaScript. I updated the question – CodyBugstein Commented Feb 15, 2013 at 19:57

Add a ment  | 

3 Answers 3

Sorted by: Reset to default 3

Just replace all the non-digits from the original string:

var s = "foo 123 bar 456";
var digits = s.replace(/\D+/g, "");

The other solutions are better, but to do it just as you asked, you simply need to join the array.

var str = "this 1 string has 2 digits";
var result = str.match(/[0-9]+/g).join(''); // 12

You can replace all the non-digits character rather than extracting the digits:

var str = "some string 22 with digits 2131";
str = str.replace(new RegExp("\D","g"),"");

\D is same as [^\d].