check type javascript

> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"

if(typeof bar === 'number') {
   //whatever
}typeof("string"); //string
typeof(123); //number//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
}if (typeof i != "number") {
    console.log('This is not number');
}console.log(typeof "how are you?")
"string"
console.log(typeof false) / console.log(typeof true)
"boolean"
console.log(typeof 100)
"number"typeof operando