Casting between Numbers and String in JavaScript

// Number to String
var tt = 2
tt += "";
alert(typeof tt);   // Result : string

// String to Number
tt = "2"
tt *= 1;
alert(typeof tt);    // Result : number

Ref. https://blog.outsider.ne.kr/361

Javascript에서 String을 Number타입으로 바꾸기 :: Outsider's Dev Story