how to use regex.test class in javascript

Question

i am doing client side validation in Zend framework2 and using regex. test class for this purpose but not getting the correct result i m using in the following way

var regex = new RegExp('/^[a-zA-Z0-9_-\s]{1,50}+$/');
console.log(regex.test(id_val));

but it always returns false. does any one knows how to use it?

The syntax looks fine. What's the value of id_val? Add that to the question. — Steve Bergamini
– Steve Bergamini, Commented Sep 30, 2013 at 12:45
Creating a RegExp object using new does not take delimiters, and two quantifiers after another are also an error. (Your browser’s JS console should have told you about the latter already.) — C3roe
– C3roe, Commented Sep 30, 2013 at 12:48

falsetru · Accepted Answer · 2013-09-30 13:07:26Z

1

Remove surrounding / from the string literal, and trailing +. Also escape \ as commented by @Bergi.

var regex = new RegExp('^[a-zA-Z0-9_-\\s]{1,50}$');
regex.test('1'); // => true

Or, use the regular expression literal:

/^[a-zA-Z0-9_-\s]{1,50}$/.test('1'); // => true

Use regular expression literal unless you need to generate regular expression runtime.

edited Sep 30, 2013 at 13:07

answered Sep 30, 2013 at 12:45

falsetru

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2 Comments

Bergi Over a year ago

…and escape the backslash. No, just use the literal instead of the constructor.

Shahbaz Over a year ago

still i m confused that how to enclosed regex in quotes as it is coming in the form of string form another page.

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