check the type of a variable in javascript code example

Example 1: javascript how to know type of variable

var foo = "Hello";
console.log(typeof foo); // string

Example 2: node js check type of variable

if (typeof i != "number") {
    console.log('This is not number');
}

Example 3: get type of var js

var x = 12345; 
console.log(typeof x) // number
x = 'string'; 
console.log(typeof x) // string
x = { key: 'value' };
console.log(typeof x) // object