Object.entries

By  on  

Navigating and managing data structures is a really important skill for every level of engineer to have and improve upon. Over the years, the JavaScript language has continued to provide more methods for managing data structures, from Object.keys to Object.values and so on. One of my favorites is Object.entries, an API that provides the keys and values via an array of arrays. Let's have a look!

Consider the following object:

const obj = {
    name: "David",
    color: "green",
    balance: 100
}

Traditionally we'd have iterated over keys via a for loop, then use array syntax to get values:

const obj = {
    name: "David",
    color: "green",
    balance: 100
}

for (const key in obj) {
    const value = obj[key];
}

We do have Object.keys() and Object.values() to get each now, but neither method provides a relationship to the parent key or value. I really love using Object.entries to maintain that relationship and get both the key and value:

Object.entries({
    name: "David",
    color: "green",
    balance: 100
}).forEach(([key, value]) => console.log(key, value))

/*
name David
color green
balance 100
*/

Object.entries is such a useful method when you need both a key and value. Throw away those old for loops and Array-like syntaxes and use Object.entries like a pro!

Recent Features

  • By
    Animated 3D Flipping Menu with CSS

    CSS animations aren't just for basic fades or sliding elements anymore -- CSS animations are capable of much more.  I've showed you how you can create an exploding logo (applied with JavaScript, but all animation is CSS), an animated Photo Stack, a sweet...

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

Incredible Demos

  • By
    Duplicate DeSandro’s CSS Effect

    I recently stumbled upon David DeSandro's website when I saw a tweet stating that someone had stolen/hotlinked his website design and code, and he decided to do the only logical thing to retaliate:  use some simple JavaScript goodness to inject unicorns into their page.

  • By
    Create a Context Menu with Dojo and Dijit

    Context menus, used in the right type of web application, can be invaluable.  They provide shortcut methods to different functionality within the application and, with just a right click, they are readily available.  Dojo's Dijit frameworks provides an easy way to create stylish, flexible context...

Discussion

  1. I had a big discussion on this over at StackOverflow : https://stackoverflow.com/q/66074709/126833

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!