Why you should use Object.is() method for equality comparison

The Object.is() method determines whether two values are the same value. The Object.is() behaves like === operator except it's behaviour with signed zeros and NaN.

Object.is() is better and precise than === strict equality operator. Object.is() useful in scenarios which includes working with NaN and signed zeroes.

Behaviour of Strict Equality Operator (===) with NaN

let amountA = NaN;
let amountB = NaN;
console.log(amountA === amountB); 
// Output
false

The strict equality considers NaN and NaN are different values. That is why it returns false.

Behaviour of Object.is() with NaN

let amountA = NaN;
let amountB = NaN;
console.log(Object.is(amountA, amountB)); 
// Output
true

Object.is() treats the NaN & NaN as same value. That is why it returns true.

Behaviour of Strict Equality Operator (===) with Signed Zeros

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

Strict equality operator === treats +0 , -0 and 0 as same values.

Behaviour of Object.is() with Signed Zeros

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

But Object.is() treats the +0 & -0 as different values. But it treats +0 &0 as same values.

Please refer the Following Equality comparison table for reference : -