From 85c54ba65d600631a1518cb63e13b1a83688e77e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Necati=20=C3=96zmen?= Date: Fri, 17 Jan 2025 14:37:33 +0300 Subject: [PATCH] docs(blog): update every for snippets (#6650) Co-authored-by: Batuhan Wilhelm --- ...-07-js-every.md => 2025-01-17-js-every.md} | 75 ++++++++++++++++++- 1 file changed, 73 insertions(+), 2 deletions(-) rename documentation/blog/{2024-02-07-js-every.md => 2025-01-17-js-every.md} (82%) diff --git a/documentation/blog/2024-02-07-js-every.md b/documentation/blog/2025-01-17-js-every.md similarity index 82% rename from documentation/blog/2024-02-07-js-every.md rename to documentation/blog/2025-01-17-js-every.md index 7cb7643c53d9..050e5a6961b1 100644 --- a/documentation/blog/2024-02-07-js-every.md +++ b/documentation/blog/2025-01-17-js-every.md @@ -4,11 +4,11 @@ description: We expound with examples what the JavaScript every method is, how i slug: javascript-every-method authors: abdullah_numan tags: [javascript] -image: https://refine.ams3.cdn.digitaloceanspaces.com/blog/2022-11-02-js-every/social.png +image: https://refine.ams3.cdn.digitaloceanspaces.com/blog/2022-11-02-js-every/social-2.png hide_table_of_contents: false --- -**_This article was last updated on February 7, 2024, to reorganize content for clarity and add new 'use cases' sections for the JavaScript 'every' method._** +_**This article was last updated on January 17, 2025, to include best practices for using the JavaScript every method, a detailed table comparing every with some, and tips for avoiding common mistakes when working with sparse arrays, empty arrays, and callbacks involving thisArg.**_ ## Introduction @@ -23,13 +23,19 @@ In this post, we expound with examples what `Array.prototype.every` is and how i Steps we'll cover: - [What is the JavaScript `Array.prototype.every` Method ?](#what-is-the-javascript-arrayprototypeevery-method-) + - [JS `Array.prototype.every`: Details of the Callback Function](#js-arrayprototypeevery-details-of-the-callback-function) + - [How JavaScript Array `every` Method Works](#how-javascript-array-every-method-works) +- [Comparison Table: JavaScript `every` vs `some`](#comparison-table-javascript-every-vs-some) - [When to Use the JS Array `every` Method](#when-to-use-the-js-array-every-method) - [JavaScript Array `every()` With `thisArg` Argument](#javascript-array-every-with-thisarg-argument) - [JavaScript Array `every(callback, thisArg)` Doesn't Work With Arrow Functions](#javascript-array-everycallback-thisarg-doesnt-work-with-arrow-functions) - [JavaScript Array `every(callback, thisArg)` Works With Non-Arrow Functions](#javascript-array-everycallback-thisarg-works-with-non-arrow-functions) - [JavaScript Array `every` Method: Modifying the Caller Array](#javascript-array-every-method-modifying-the-caller-array) - [Nuances of Using JS Array `every` Method](#nuances-of-using-js-array-every-method) + - [The JS `Array.prototype.every`: Using with Sparse Arrays](#the-js-arrayprototypeevery-using-with-sparse-arrays) + - [Using JavaScript `every` With Empty Arrays](#using-javascript-every-with-empty-arrays) - [Difference Between Some and Every in JavaScript?](#difference-between-some-and-every-in-javascript) +- [When Should You Use the JavaScript every Method?](#when-should-you-use-the-javascript-every-method) ## What is the JavaScript `Array.prototype.every` Method ? @@ -75,6 +81,17 @@ console.log(areAllDoubledEven); // true In the chunk of code above, `even` is our callback function, which we pass to `every()`. Apparently, we have at least one odd number in our `numbers` array and so not all elements pass the test. So, `every()` returns `false` for `areAllEven`. In contrast, all items in `numbersDoubled` are even, so we get `true` for `areAllDoubledEven`. +## Comparison Table: JavaScript `every` vs `some` + +| Feature | `every` Method | `some` Method | +| ------------------ | ------------------------------------------ | ---------------------------------------------------- | +| **Purpose** | Tests if **all** elements pass a condition | Tests if **at least one** element passes a condition | +| **Returns** | `true` if all elements pass the test | `true` if any element passes the test | +| **Stops Checking** | At the first failing element | At the first passing element | +| **Empty Arrays** | Always returns `true` | Always returns `false` | + +You can now directly copy and paste this table into your Markdown editor! + ## When to Use the JS Array `every` Method The JS Array `every` method can be used in a wide range of scenarios where we need to verify that all items, with no exception, satisfy the test specified in the callback function. In all cases, the first argument (`element`) has to be passed to the callback. The complexity of the test would determine whether to access the second (`index`), third arguments (`array`), or any additional argument via the `thisArg` object. @@ -348,6 +365,60 @@ In JavaScript, `some()` returns `true` if any array element meets a condition, w - Returns `true` only if all elements pass the test, otherwise `false`. - Stops checking once it finds a failing element. +## When Should You Use the JavaScript every Method? + +### Data Validation + +Use it to check if all form fields are filled in: + +```javascript +const fields = ["email@example.com", "password123"]; +const allFieldsFilled = fields.every((field) => field.trim() !== ""); +console.log(allFieldsFilled); // true if no empty fields +``` + +### Check Data Types + +Confirm that an array contains only numbers: + +```javascript +const data = [1, 2, 3]; +const allNumbers = data.every((item) => typeof item === "number"); +console.log(allNumbers); // true +``` + +### Team Permissions + +Verify if all team members have admin roles: + +```javascript +const team = [{ role: "admin" }, { role: "admin" }]; +const allAdmins = team.every((member) => member.role === "admin"); +console.log(allAdmins); // true +``` + +## FAQs About the JavaScript every Method + +### 1. What is the purpose of the every method in JavaScript? + +This checks whether all the elements in an array pass a test provided in a callback function. If all pass, it returns true; otherwise, false. + +### 2. Does the every method work for empty arrays? + +Yes, this always returns true for empty arrays since there are no elements that could fail the condition. + +### 3. Can the every method modify the array? + +No, the method itself doesn't change the array. However, the array can change inside the callback function. + +### 4. What is the difference between every and some? + +every checks if all elements meet the condition, while some checks if at least one element meets the condition. + +### 5. Does the every Method Work with Objects? + +Yes, but you would need to access the object properties in the callback function to test them. + ## Summary In this article, we explored in depth the **JavaScript every** which helps us test whether all items in an array pass the test we implement in a callback function. We saw with examples that the callback function can take three arguments, and additional arguments can be bound to its execution context by setting its `this` value with a `thisArg` passed to `every()` as the second argument.