Object.is() provides a true comparison for any object. Start using it today if you have missed out so far..!

Consider the code below -

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console.log("abc" == "abc"); // true
console.log(null == null); // true
console.log(1 == 1); // true
// break
console.log(0 == false); // true
console.log("" == false); // true

While we are ok with the statements above break, the statements below can cause a problem.

Typically this is overcome by using strict comparison -

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console.log("abc" === "abc"); // true
console.log(null === null); // true
console.log(1 === 1); // true
console.log(0 === false); // false
console.log("" === false); // false

But, what about the only edge case that is so.. so.. so important -

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console.log(NaN == NaN); // false
console.log(0 === -0); // true

Will you use ==, ===, invent your own ====, or just get flustered enough to ignore the edges?

Now* you may not do any of those things. Object.is() is here.

Object.is() not only solves the most common equality problems..

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console.log(Object.is(null, null)); // true
console.log(Object.is(1, 1)); // true
console.log(Object.is("abc", "abc")); // true

But also, solves the ‘super important’, ‘most commonly used’ edge cases.

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console.log(Object.is(NaN, NaN)); // true
console.log(Object.is(+0, -0)); // false

Simply do Object.is everywhere and sleep peacefully at night..

Or.. no. Hold on a minute - how about those pesky objects?

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console.log(Object.is({ name: "apple" }, { name: "apple" })); // false
console.log(Object.is([1, 2, 3], [1, 2, 3])); // false

Objects still work on the same principle - you need to manually compare values. Object.is() cannot convert the reference properties of an object magically. Give it a break, y’all.

* now = circa ES6. I am late to the party, can’t keep track of everything now.

Also see

• Array comparison in Javascript
• Cycling through Objects in Javscript
• Check empty objects