why javascript regexp doesn't match

Question

(new RegExp('/videos/(\d+)$')).test('/videos/1') returns false. Why?

(new RegExp('/videos/(\d+)$')) == /\/videos\/(d+)$/

begins with /, then goes videos string, then / again and then d+ which is 1 or more digits, so 1 should match...

Paul Roub · Accepted Answer · 2015-03-26 21:46:06Z

3

You need to escape the \\:

console.log( (new RegExp('/videos/(\\d+)$')).test('/videos/1') );

answered Mar 26, 2015 at 21:46

Paul Roub

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Comments

bvaughn · Accepted Answer · 2015-03-26 21:46:26Z

0

This works:

var s = '/videos/1';
s.match(/\/videos\/(\d+)$/);

As does this:

var regex = new RegExp(/\/videos\/(\d+)$/)
regex.test('/videos/1')

Are you seeing something different?

answered Mar 26, 2015 at 21:46

bvaughn

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Wiktor Stribiżew · Accepted Answer · 2015-03-26 21:52:35Z

0

You should escape special characters in a RegExp constructor:

alert((new RegExp("\\/videos\\/(\\d+)$")).test('/videos/1'))

When using the constructor function, the normal string escape rules (preceding special characters with \ when included in a string) are necessary.

answered Mar 26, 2015 at 21:45

Wiktor Stribiżew

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