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the answer is wrong for the question: "How do you compare two objects in JavaScript?"

See original GitHub issue

The code can’t work by calling

isDeepEqual(1, 2)

This is my answer:

function isDeepEqual(obj1, obj2, testPrototypes = false) {
    if (obj1 === obj2) {
        return true;
    if (type(obj1) === 'Function' && type(obj2) === 'Function') {
        return obj.toString() === obj2.toString();
    if (type(obj1) === 'Date' && type(obj2) === 'Date') {
        return obj1.getTime() === obj2.getTime();
    if (type(obj1) !== type(obj2) || type(obj1) !== 'object') {
        return false;

    const prototypesAreEqual = testPrototypes
        ? isDeepEqual(
        : true;

    const obj1Props = Object.getOwnPropertyNames(obj1);
    const obj2Props = Object.getOwnPropertyNames(obj2);

    return (
        obj1Props.length === obj2Props.length &&
        prototypesAreEqual &&
        obj1Props.every(prop => isDeepEqual(obj1[prop], obj2[prop]))

function type(obj) {

Issue Analytics

  • State:closed
  • Created 5 years ago
  • Comments:9 (8 by maintainers)

github_iconTop GitHub Comments

skatcat31commented, Sep 9, 2018

right never reported test results did I… yeah it’s working in all cases. Never found an edge case that could be considered a problem except for a SO if I went deep with auto generating object references

skatcat31commented, Sep 1, 2018

The one you’ve submitted in the PR seems to be working. I want to do some more in depth tests when I have some time or if you’d like to submit some tests for it in the PR as a comment on the thread I’d be more than happy to look it over. Either way, this is a helpful find!

Read more comments on GitHub >

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