Jquery - Convert string to reg exp object

Question

My regular expression is /^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/ and in html I added it as a hidden element with the value of the element set to the above pattern

When I do this:

var regex = /^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/ 
var text = $(this).val()

and then test with regex.test(text) it works fine.

but when I assign regex like this:

var regex = $("#m"+id).val() // (my hidden element)

then it doesnt work. I have tried assigning it using new RegExp as well but also not working.I think it's doing it because it's returning the value as a string from $("#m"+id).val() (I am getting the right value returned here), but not sure what to parse it to.

Any help would be appreciated.

Danil Speransky · Accepted Answer · 2012-09-04 06:14:09Z

1

If you want to build regexp from string, then use Constructor of RegExp class, it takes string without slashes, so you should remove them. .slice(1, -1) removes first and last charecters. Try to use this:

var regex = new RegExp($("#m"+id).val().slice(1, -1));

answered Sep 4, 2012 at 6:14

Danil Speransky

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LeJared · Accepted Answer · 2012-09-04 06:15:52Z

0

Try:

var regex = new RegExp($("#m"+id).val())

answered Sep 4, 2012 at 6:15

LeJared

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Guffa · Accepted Answer · 2012-09-04 06:16:40Z

0

The slashes at the beginning and the end are only used when it is a regex literal. Remove them to get the actual regular expression, then you can use new RegExp(str) to turn the string into a regex object.

answered Sep 4, 2012 at 6:16

Guffa

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