JavaScript Object Equality: What's the Difference Between `==` and `===`?

What's the Difference Between Regular and Strict Object Equality?

In JavaScript, comparing objects with the regular (==) or strict (===) equality operators may not yield the expected results. Unlike primitive data types, objects are referenced by their memory address. Therefore, comparison based solely on their values is not sufficient.

Consider the following code:

var a = {};
var b = {};

console.log(a == b); // false
console.log(a === b); // false

Although both a and b are empty objects, their references point to different memory addresses. Consequently, both regular and strict equality evaluations return false.

Why is this Important?

Understanding this nuance is crucial for ensuring accurate object comparisons. Objects should only be considered equal if they reference the exact same memory address. Assigning an object to a new variable creates a new reference, even if the contents are identical.

For instance, let's say we have three objects: a, b, and c.

a = {}
b = a
c = {}

In this case, a == a, a == b, and a != c. This is because a and b reference the same memory address, while c has its own unique reference.

Conclusion

When comparing objects, it's essential to remember that object equality is based on memory references, not their values. Regular and strict equality operators behave the same for objects, and they only return true if the objects being compared reference the same memory address.

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