Answers for "is undefined == null"

js is undefined or null

var myVar=null;

if(myVar === null){
    //I am null;
}

if (typeof myVar === 'undefined'){
    //myVar is undefined
}

null + undefined

console.log(null === null);  // true
  console.log(undefined === undefined);  // true
  console.log(null + undefined === null + undefined); // false

// null + undfined equals NaN, and NaN isn't equal to itself :(