The Perplexity of Object Equality
Despite sharing identical characteristics, two seemingly identical objects remain unequal in JavaScript. This phenomenon has perplexed many, given the code snippet below:
var a = {}; var b = {}; console.log(a==b); //returns false console.log(a===b); //returns false
Understanding Equality Operators
The disparity between the results of the regular (==) and strict (===) equality operators lies in type conversion. Regular equality performs implicit type conversion, while strict equality does not. However, in this case, both variables are objects, so type conversion is irrelevant.
Object Identity
Object comparisons evaluate to true only when comparing the same object reference, regardless of the equality operator used. In other words, a == a, a == b (if b is an alias of a), but a != c (if c is a different object).
Implications
This unique behavior has implications for object-oriented programming. Two objects with identical properties but different references are considered unequal, even if they represent the same real-world entity.
For example, in a database, two objects representing the same person with the same name, address, and phone number would not be considered equal, as they have different object references. This can lead to confusing results when performing object comparisons.
Solutions
If comparing the properties of two objects is necessary, consider using a third-party library or implementing a custom comparison function that checks each property individually.
Disclaimer: All resources provided are partly from the Internet. If there is any infringement of your copyright or other rights and interests, please explain the detailed reasons and provide proof of copyright or rights and interests and then send it to the email: [email protected] We will handle it for you as soon as possible.
Copyright© 2022 湘ICP备2022001581号-3