CODEWITHSUNDEEP
javascriptregex
Nikita Harlov
Nikita Harlov

Reputation: 25

Javascript regexp does not work

Test string is "page-42440233_45778105" pattern "(page-\d+_\d+)"

Online tester(http://www.regexr.com/) successfuly finded mathc,but in browser js result is null. Why?

var re = new RegExp("(page-\d+_\d+)", "gim");
var r_array = message.match(re);
console.log(r_array);

Upvotes: 0

Views: 63

Answers (3)

maček
maček

Reputation: 77778

I think this would be a better pattern

var re = /^page-\d+_\d+$/i;

It also matches the beginning (^) and end ($) of the string

message.match(re);
//=> ["page-42440233_45778105"]

Upvotes: 1

falsetru
falsetru

Reputation: 369034

You need to escape \ if you use string literal:

var message = "page-42440233_45778105";
var re = new RegExp("(page-\\d+_\\d+)", "gim");
var r_array = message.match(re);
console.log(r_array);
// => ["page-42440233_45778105"]

More preferably, use regular expression literal:

var re = /(page-\d+_\d+)/gim;

Upvotes: 0

Denys Séguret
Denys Séguret

Reputation: 382112

When you use a string literal, you must escape the \ : 

var re = new RegExp("(page-\\d+_\\d+)", "gim");

A better solution here would be to use a regex literal :

var re = /(page-\d+_\d+)/gim

Don't use the RegExp constructor if the regular expression is constant, regex literals are much more convenient.

Upvotes: 0

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