Typeof Cheatsheet in Javascript

Here’s a quick reference of various values and their types.

For further reference: see what types mean in Javascript and type casting in Javascript.

Value	Type	Description
true	boolean	Boolean
1	number	Number
“1”	string	String
“abcd”	string	String
Boolean(false)	object	Boolean object
Number(0)	object	Number object
String(“abcd”)	object	String object
[1, 2, 3]	object	Array object
Object()	object	Plain object
{}	object	Plain object
function() {}	function	Function object

Code to cross-check -

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15


console.log(typeof true); // boolean
console.log(typeof 1); // number
console.log(typeof 3.14); // number
console.log(typeof "1"); // string
console.log(typeof "abcd"); // string

console.log(">> Objects <<");
console.log(typeof new Boolean(false)); // object
console.log(typeof new Number(0)); // object
console.log(typeof new String("abcd")); // object

console.log(typeof [1, 2, 3]); // object
console.log(typeof new Object()); // object
console.log(typeof {}); // object
console.log(typeof function() {}); // function

The only objective of the above table is to provide an overview of what you can expect when working with the loose-typing in Javascript.

Often times you don’t care about types in Javascript - I get that.

Typeof Cheatsheet in Javascript

See Also