type checking in javascript

Question

How can I check if a variable is currently an integer type? I've looked for some sort of resource for this and I think the === operator is important, but I'm not sure how to check if a variable is an Integer (or an Array for that matter)

Answer 1

A variable will never be an integer type in JavaScript — it doesn't distinguish between different types of Number.

You can test if the variable contains a number, and if that number is an integer.

(typeof foo === "number") && Math.floor(foo) === foo

If the variable might be a string containing an integer and you want to see if that is the case:

foo == parseInt(foo, 10)