How do I compare two JavaScript objects for equality?

How do I compare two JavaScript objects for equality?

In JavaScript, you can compare objects using various methods. The simplest way is to use JSON.stringify, but it has limitations.

What are the limitations of using JSON.stringify for comparison?

JSON.stringify won't work for objects with functions, undefined values, or circular references. It also doesn't consider property order.

Is there a better way to compare objects?

Yes, you can use libraries like Lodash's isEqual function, or write a custom deep comparison function.

Can you show me an example of a deep comparison function?

Sure! Here's a simple deep comparison function:

function deepEqual(obj1, obj2) {
    if (obj1 === obj2) return true;
    if (obj1 == null || obj2 == null) return false;
    if (typeof obj1 !== 'object' || typeof obj2 !== 'object') return false;
    const keys1 = Object.keys(obj1);
    const keys2 = Object.keys(obj2);
    if (keys1.length !== keys2.length) return false;
    for (let key of keys1) {
        if (!keys2.includes(key) || !deepEqual(obj1[key], obj2[key])) return false;
    }
    return true;
}