: vs = in js code example

Example 1: != vs !== javascript

(0 ==  '0') // true
(0 === '0') // false

('' ==  0 ) // true, the string will implicitly be converted to an integer
('' === 0 ) // false, no implicit cast is being made

Example 2: javascript !! vs !

// !! used for checking availability of data 
!!'hello' // true