How to match an index of a CSS class with JavaScript?

Question

I want to match the index of a CSS class.

Example:

Given string: .item.item-3.layer.layer-1.test

Desired result: 3 (the index following the class "item")

But my current RegEx just gives me the index of the last class with a dash:

var matches = destinationClass.match(/[^-]+$/);
console.log(matches[0]);

Can anyone help me?

Answer 1

var matches = destinationClass.match(/item-([0-9]+)/);
console.log(matches[1]);

matches[1] gives the substring corresponding the part of pattern enclosed in parentheses

Answer 2

You could simplify your regex to:

match(/item-([0-9]+)/).pop()