Home Web Front-end Front-end Q&A The fastest way to remove duplicates from an array in javascript

The fastest way to remove duplicates from an array in javascript

May 16, 2023 am 09:40 AM

As a scripting language, JavaScript is widely used in Web development and front-end UI design because it is easy to read and write. As a common data structure, arrays often play an important role in the use of JavaScript, such as traversing in loops, sorting, etc. When performing array operations, we often encounter duplication of array elements. At this time, we need to perform deduplication operations on the array.

So, how to deduplicate JavaScript arrays fastest?

Method 1: Use Set (ES6)

In native JavaScript, Set solves the problem of array deduplication very well. It can quickly complete deduplication for an unknown number of element collections. and sorting operations. The following is the code implementation using Set to remove duplicates:

let uniqueArray = Array.from(new Set(originalArray)); 
Copy after login

Or it can be written as

let uniqueArray= [...new Set(originalArray)]; 
Copy after login

Among them, the Array.from() method is used to convert the Set into an array, and [...] is The spread operator is a way to directly convert a Set into an array.

The deduplication method using Set has simple code and is more efficient when processing large-scale arrays. However, this method is not very compatible with IE browser, so it is recommended to check whether the browser supports Set before use.

Method 2: Use indexOf

Using the indexOf method can easily determine whether the array element exists, thereby realizing the array deduplication function. The following is the code for using indexOf to implement array deduplication:

let uniqueArray = [];
for(let i = 0; i < originalArray.length; i++){
    if(uniqueArray.indexOf(originalArray[i]) === -1){
        uniqueArray.push(originalArray[i]);
    }
}
Copy after login

In this implementation, we use the array uniqueArray to store unique elements, traverse the original array originalArray, and determine whether the elements in it already exist in the uniqueArray. If it does not exist, add it to uniqueArray.

Although the code size of this method is slightly complex, it is very fast on smaller arrays because it only needs to be looped once.

Method 3: Use the new ES6 method includes

ES6 has a new includes method, which can be used to check whether the array contains a certain element. The includes method is faster than indexOf when processing large arrays. many. The following is the code for using includes to implement array deduplication:

let uniqueArray = [];
for(let i = 0; i < originalArray.length; i++){
    if(!uniqueArray.includes(originalArray[i])){
        uniqueArray.push(originalArray[i]);
    }
}
Copy after login

Similar to the indexOf method, this implementation also uses a new array uniqueArray to store non-duplicate elements. This approach is readable and allows for fast deduplication in large arrays.

Conclusion

Among the above three methods, using Set is the simplest and fastest. But it should be noted that you need to check whether the browser is compatible with Set. The indexOf method is more readable, but only suitable for small arrays. Using ES6's includes method can handle large arrays, and it is also shorter and easier to read.

In actual projects, try to use different methods and choose the method that best suits you according to the actual situation.

The above is the detailed content of The fastest way to remove duplicates from an array in javascript. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

What is useEffect? How do you use it to perform side effects? What is useEffect? How do you use it to perform side effects? Mar 19, 2025 pm 03:58 PM

The article discusses useEffect in React, a hook for managing side effects like data fetching and DOM manipulation in functional components. It explains usage, common side effects, and cleanup to prevent issues like memory leaks.

Explain the concept of lazy loading. Explain the concept of lazy loading. Mar 13, 2025 pm 07:47 PM

Lazy loading delays loading of content until needed, improving web performance and user experience by reducing initial load times and server load.

What are higher-order functions in JavaScript, and how can they be used to write more concise and reusable code? What are higher-order functions in JavaScript, and how can they be used to write more concise and reusable code? Mar 18, 2025 pm 01:44 PM

Higher-order functions in JavaScript enhance code conciseness, reusability, modularity, and performance through abstraction, common patterns, and optimization techniques.

How does currying work in JavaScript, and what are its benefits? How does currying work in JavaScript, and what are its benefits? Mar 18, 2025 pm 01:45 PM

The article discusses currying in JavaScript, a technique transforming multi-argument functions into single-argument function sequences. It explores currying's implementation, benefits like partial application, and practical uses, enhancing code read

How does the React reconciliation algorithm work? How does the React reconciliation algorithm work? Mar 18, 2025 pm 01:58 PM

The article explains React's reconciliation algorithm, which efficiently updates the DOM by comparing Virtual DOM trees. It discusses performance benefits, optimization techniques, and impacts on user experience.Character count: 159

What is useContext? How do you use it to share state between components? What is useContext? How do you use it to share state between components? Mar 19, 2025 pm 03:59 PM

The article explains useContext in React, which simplifies state management by avoiding prop drilling. It discusses benefits like centralized state and performance improvements through reduced re-renders.

How do you prevent default behavior in event handlers? How do you prevent default behavior in event handlers? Mar 19, 2025 pm 04:10 PM

Article discusses preventing default behavior in event handlers using preventDefault() method, its benefits like enhanced user experience, and potential issues like accessibility concerns.

What are the advantages and disadvantages of controlled and uncontrolled components? What are the advantages and disadvantages of controlled and uncontrolled components? Mar 19, 2025 pm 04:16 PM

The article discusses the advantages and disadvantages of controlled and uncontrolled components in React, focusing on aspects like predictability, performance, and use cases. It advises on factors to consider when choosing between them.

See all articles