JavaScript typeof Operator

The typeof operator returns the type of variables and values. For example,

const a = 9;

console.log(typeof a); // number
console.log(typeof '9'); // string
console.log(typeof false); // boolean

Syntax of typeof Operator

The syntax of typeof operator is:

typeof operand

Here, operand is a variable name or a value.

typeof Types

The possible types that are available in JavaScript that typeof operator returns are:

Example 1: typeof for String

Example 2: typeof for Number

Example 3: typeof for BigInt

Example 4: typeof for Boolean

Example 5: typeof for Undefined

Example 6: typeof for null

Example 7: typeof for Symbol

Example 8: typeof for Object

Example 9: typeof for Function

Uses of typeof Operator

• The typeof operator can be used to check the type of a variable at a particular point. For example,

let count = 4;
console.log(typeof count);

count = true;
console.log(typeof count);

• You can perform different actions for different types of data. For example,

let count = 4;
if(typeof count === 'number') {
    // perform some action
}
else if (typeof count = 'boolean') {
      // perform another action
}