regex to get the number from the end of a string

i have a id like stringNumber variable like the one as follows : example12 I need some javascript regex to extract 12 from the string."example" will be constant for all id and just the number will be different.

2 Answers

This regular expression matches numbers at the end of the string.

var matches = str.match(/\d+$/); 

It will return an Array with its 0th element the match, if successful. Otherwise, it will return null.

Before accessing the 0 member, ensure the match was made.

if (matches) { number = matches[0]; } 

jsFiddle.

If you must have it as a Number, you can use a function to convert it, such as parseInt().

number = parseInt(number, 10); 

RegEx:

var str = "example12"; parseInt(str.match(/\d+$/)[0], 10); 

String manipulation:

var str = "example12", prefix = "example"; parseInt(str.substring(prefix.length), 10);