Comparing numbers to numbers as strings

Question

I was trying to figure out why my CoffeeScript code was not working:

HTML:

<a data-id="5">Click me</a>

CoffeeScript:

id = $('a').attr('data-id')
console.log id == 5

The problem is the number being returned from attr('data-id') is a string and comparing it to an actual number fails the comparison. What should I be doing differently so that I can easily compare numbers.

Answer 1

You may use parseFloat or parseInt methods, and also take a look at jQuery data method which tries to convert content of data- attribute to appropriate data type

id = $('a').data('id')
console.log id == 5

Answer 2

Same way you do in Javascript

id = '5'
console.log parseInt(id, 10) == 5 # parseInt() parses a string as an integer
console.log +id == 5              # + prefix is an "interpret as number" shorthand
console.log id == 5.toString()    # Or convert the other number to a string

Run this here, all report true