Parsing an Int from a string in javascript

Question

In javascript, what is the best way to parse an INT from a string which starts with a letter (such as "test[123]")? I need something that will work for the example below.

My JS:

$(document).ready(function() {

    $(':input').change( function() {
     id = parseInt($(this).attr("id"));  //fails for the data below
     alert(id);
    });
}

My generated HTML:

<select id="attribute[123]">
<!-- various options -->
</select>
<select id="attribute[456]">
<!-- various options -->
</select>

Thank you!

Answer 1

parseInt(input.replace(/[^0-9-]/,""),10)

Answer 2

Probably just filter out the string with .replace(). If there is another way then I am unaware of it:

parseInt("attribute[123]".replace("attribute[", "").replace("]", "")));

You could probably use some Regex to put that in only one .replace(), but I'm not good with Regex so I just did it twice.

Test this in your browser with

javascript:alert(parseInt("attribute[123]".replace("attribute[", "").replace("]", "")));

Should alert 123.

Answer 3

You could use a regular expression to match the number:

$(this).attr("id").match(/\d+/)