Difference between == and === in JavaScript

막연하게 이해하고 썼는데, 

아래 예시가 가장 이해하기 편한 듯!!

1116down vote

Take a look here: http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html The 3 equal signs mean "equality without type coercion". Using the triple equals, the values must be equal in type as well. 0 == false // true 0 === false // false, because they are of a different type 1 == "1" // true, automatic type conversion for value only 1 === "1" // false, because they are of a different type null == undefined // true null === undefined // false '0' == false // true '0' === false // false

http://stackoverflow.com/questions/523643/difference-between-and-in-javascript

한마디로 정리하자면,

=== 이 == 에 비해서 타입 검사까지 하기 때문에 훨씬 엄격하다(strict).