How to check that (sub)string is a number in javascript?

Question

There is lots of answers for that question on SO but none for javascript...

How can I check if first 16 characters of this sting 20130203003002od is a number? Meaning that the substring doesn't contains any letters nor any other characters but digits?

Somebody suggested isNaN(value) function. But this comment was removed any idea why? — Radek
– Radek, Commented Feb 11, 2013 at 22:43
because the asker is only interested in finding if the first 16 characters contain only digits. isNaN('0xf'), for example will return false (meaning it is a number) and that isn't what the asker wanted since x and f aren't digits. — Casey Foster
– Casey Foster, Commented Feb 13, 2013 at 15:36

Casey Foster · Accepted Answer · 2013-02-11 22:39:57Z

6

if first 16 characters ... [don't contain] any letters nor any other characters but digits

/^\d{16}/.test(str);

should work.

answered Feb 11, 2013 at 22:39

Casey Foster

6,0402 gold badges29 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

nikeaa · Accepted Answer · 2013-02-11 22:47:13Z

1

You could test the string against a regular expression like so:

var data = "20130203003002od";
var matched = data.match("[0-9]{16}.*");

If matched is NULL, that means that the first 16 characters are not a number.

answered Feb 11, 2013 at 22:47

nikeaa

1,0477 silver badges17 bronze badges

1 Comment

Radek Over a year ago

I like your answer. Thank you. Works nicely.

Collectives™ on Stack Overflow

How to check that (sub)string is a number in javascript?

2 Answers 2

Comments

1 Comment

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Related