JS: Object.is

(new in JS: ECMAScript 2015)

Object.is(value1, value2)

return true if two values are equal.

similar to Triple Equal Operator , but can distinguish negative zero and positive zero, and two NaN are considered equal.

// negative zero and positive zero

console.log(Object.is(-0, +0) === false);

console.log((-0 === +0) === true);

// testing equality of two NaN

console.log(Object.is(NaN, NaN) === true);

console.log((NaN === NaN) === false);