how to check number valid number in javascript code example

Example 1: if parameter is not number in js

let num1 = 'Hello';
if(isNaN(num1)){
    console.log(num1 + ' is not a number');
} else{
    console.log(num1 + ' is a number');
}

Example 2: js check if string or int

var myString     =  "abc123";
var otherString  =  "123";
/* isInterger() checks if an value repersents an int  */

Number.isInteger(myString);    //returns false
Number.isInteger(otherString); //returns true