how to get type of variable in javascript

var foo = "Hello";
console.log(typeof foo); // string// get type of variable

var number = 1
var string = 'hello world'
var dict = {a: 1, b: 2, c: 3}

console.log(typeof number) // number
console.log(typeof string) // string
console.log(typeof dict)   // objectfunction doSomething(x) {
  if(typeof(x) === 'string') {
    alert('x is a string')
  } else if(typeof(x) === 'number') {
    alert('x is a number')
  }
}> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"

if(typeof bar === 'number') {
   //whatever
}//typeof() will return the type of value in it's parameters.
//some examples of types: undefined, NaN, number, string, object, array

//example of a practical usage
if (typeof(value) !== "undefined") {//asuming value is already set
  	//execute code
}> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"