Check if string starts with a number [duplicate]

Question

How would I do something like this in javascript:

var s = '124sdg'; var f = 'hsdsda'; if (s.startsWith(a number)) { // Return true } if (f.startsWith(a number)) { // Return false }

redneb · Accepted Answer · 2016-09-28 00:19:47Z

43

You can use a regular expression:

if (s.match(/^\d/)) { // Return true } if (f.match(/^\d/)) { // Return false }

answered Sep 28, 2016 at 0:19

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2 Comments

This answer is overrated. If we only need to check the regex against the value, .test performs better. Please refer here.

Yes, agreed, test is better here.

Keith Nicholas · Accepted Answer · 2016-09-28 00:21:18Z

28

use a regex...

/^\d/.test(s)

which will return true or false if the first digit is a number or not

answered Sep 28, 2016 at 0:21

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