test if a variable is a primitive rather than an object? [duplicate]

Question

Is it possible to test a variable to see if it is a primitive?

I have seen lots of questions about testing an variable to see if it is an object, but not testing for a primitive.

This question is academic, I don't actually need to perform this test from my own code. I'm just trying to get a deeper understanding of JavaScript.

Answer 1

To test for any primitive:

function isPrimitive(test) {     return test !== Object(test); } 

Example:

isPrimitive(100); // true isPrimitive(new Number(100)); // false 

http://jsfiddle.net/kieranpotts/dy791s96/

Answer 2

Object accepts an argument and returns if it is an object, or returns an object otherwise.

Then, you can use a strict equality comparison, which compares types and values.

If value was an object, Object(value) will be the same object, so value === Object(value). If value wasn't an object, value !== Object(value) because they will have different types.

So you can use

Object(value) !== value