check if is digit javascript code example

Example 1: integer check in javascript

var a=Number.isInteger(5); //True
var b= Number.isInteger(01); //True
var c=Number.isInteger("10"); //False

console.log(a,b,c);  //true true false

Example 2: check if input is a number javascript

// Another option is typeof which return a string
if (typeof(val) === 'number') {
	// Guess what, it's a bloody number!
}

Example 3: javascript check if variable is number

function isNumber(n) {
  return !isNaN(parseFloat(n)) && !isNaN(n - 0);
}