How to implement chaining in JavaScript?

---

⭐ Column introduction

Front-end entry journey: Explore the wonderful world of web development. Remember to click on the link above or on the right to subscribe to this column. Geometry will take you on a front-end journey.

Welcome to the front-end entry journey! This column is tailor-made for those who are interested in web development and have just entered the front-end field. Whether you are a complete novice or a developer with some basic knowledge, here will provide you with a systematic and friendly learning platform. In this column, we will update it every day in the form of questions and answers, presenting you with selected front-end knowledge points and answers to frequently asked questions. Through the Q&A format, we hope to respond more directly to readers’ questions about front-end technology and help everyone gradually establish a solid foundation. Whether it's HTML, CSS, JavaScript, or various common frameworks and tools, we'll explain concepts in a simple and easy-to-understand way, and provide practical examples and exercises to solidify what you've learned. At the same time, we will also share some practical tips and best practices to help you better understand and apply various technologies in front-end development.

Not only that, we will also regularly launch some practical project tutorials so that you can apply the knowledge you have learned to actual development. Through the practice of actual projects, you will be able to better understand the workflow and methodology of front-end development, and develop your own ability to solve problems and develop independently. We believe that only by continuous accumulation and practice can we truly master front-end development technology. So, get ready for the challenge and bravely embark on this front-end entry journey! Whether you are looking for a career change, upskilling or fulfilling personal interests, we are dedicated to providing you with the best learning resources and support. Let's explore the wonderful world of web development together! Join the front-end entry journey and become an outstanding front-end developer! Let’s start the front-end journey

---

⭐Chained calls in JavaScript

Chaining is a common coding pattern in JavaScript that allows you to call multiple methods in succession by returning the object itself between method calls. This pattern is widely used in many libraries and frameworks, such as jQuery and D3.js. Below are the steps and examples to implement chained calls.

• Ensure that each method returns the object itself
  . To implement chained calls, you first need to ensure that each method returns the object itself. This allows you to continue calling the next method after one method call.

• Returning Object at the End of Method
  At the end of each method, use return thisto return the current object. This is the key to chaining calls, as it allows you to continue calling other methods on the returned object.

---

⭐ Example

class Calculator {
    
    
  constructor() {
    
    
    this.value = 0;
  }

  add(num) {
    
    
    this.value += num;
    return this; // 返回当前对象，以支持链式调用
  }

  subtract(num) {
    
    
    this.value -= num;
    return this;
  }

  multiply(num) {
    
    
    this.value *= num;
    return this;
  }

  divide(num) {
    
    
    this.value /= num;
    return this;
  }

  getValue() {
    
    
    return this.value;
  }
}

const calc = new Calculator();
const result = calc.add(5).multiply(2).subtract(3).divide(2).getValue();

console.log(result); // 输出：4

In the above example, Calculatoreach method in the class returns this, allowing these methods to be called consecutively in an expression, ultimately resulting in a calculated result. This is an elegant programming method, especially suitable for situations where multiple method calls are required, because it can reduce the nesting level of the code and improve the readability of the code. Note that the order of method calls in a chain is executed from left to right, so the order in the method chain is important.

---

⭐Write at the end

This column is suitable for a wide range of readers, and is suitable for front-end beginners; or those who have not learned front-end and are interested in front-end, or back-end students who want to better show themselves and expand some front-end knowledge points during the interview process, so If you have the basics of front-end and follow this column, it can also help you to a great extent to check for omissions and fill in the gaps. Since the blogger himself does the content output, if there are any flaws in the article, you can contact me through the left side of the homepage. , let’s make progress together, and at the same time, I also recommend several columns to everyone. Interested partners can subscribe: In addition to the columns below, you can also go to my homepage to see other columns;

Front-end games (free) This column will take you into a world full of creativity and fun. By using the basic knowledge of HTML, CSS and JavaScript, we will build various interesting page games together. Whether you are a beginner or have some front-end development experience, this column is for you. We'll start with the basics and walk you through the skills you need to build a page game. Through practical cases and exercises, you will learn how to use HTML to build page structure, use CSS to beautify the game interface, and use JavaScript to add interactive and dynamic effects to the game. In this column, we'll cover various types of mini-games, including maze games, brick breaker, snake, minesweeper, calculators, plane battles, tic-tac-toe, puzzles, mazes, and more. Each project guides you through the building process in concise and clear steps, with detailed explanations and code examples. At the same time, we will also share some optimization tips and best practices to help you improve page performance and user experience. Whether you are looking for an interesting project to exercise your front-end skills, or are interested in page game development, the front-end games column will be your best choice. Click to subscribe to the front-end games column

Vue3 Transparent Tutorial [From Zero to One] (Paid) Welcome to the Vue3 Transparent Tutorial! This column aims to provide everyone with comprehensive technical knowledge related to Vue3. If you have some Vue2 experience, this column can help you master the core concepts and usage of Vue3. We will start from scratch and guide you step by step to build a complete Vue application. Through practical cases and exercises, you will learn how to use Vue3's template syntax, component development, state management, routing and other functions. We will also introduce some advanced features, such as Composition API and Teleport, to help you better understand and apply the new features of Vue3. In this column, we'll guide you through each project in concise and clear steps, with detailed explanations and sample code. At the same time, we will also share some common problems and solutions in Vue3 development to help you overcome difficulties and improve development efficiency. Whether you want to learn Vue3 in depth or need a comprehensive guide to building a front-end project, the Vue3 thorough tutorial column will become an indispensable resource for you. Click to subscribe to the Vue3 Transparent Tutorial [From Zero to One] column

TypeScript Getting Started Guide (Free) is a column designed to help you quickly get started and master TypeScript related technologies. Through concise and clear language and rich sample code, we will explain the basic concepts, syntax and features of TypeScript in depth. Whether you are a beginner or an experienced developer, you can find a learning path that suits you here. From core features such as type annotations, interfaces, and classes to modular development, tool configuration, and integration with common front-end frameworks, we will comprehensively cover all aspects. By reading this column, you will be able to improve the reliability and maintainability of JavaScript code, and provide better code quality and development efficiency for your projects. Let’s embark on this exciting and challenging TypeScript journey together! Click to subscribe to the TypeScript Getting Started Guide column

Geometry book 81 issue

Tsinghua News Agency [Autumn Reading Plan] receive coupons and enjoy instant discounts; 5 folds of IT good books plus a 10 yuan no-threshold coupon: https://u.jd.com/Yqsd9wj Event time: September 4th to September 17th , first come first served, hurry up and grab it

Participation method: Just leave a comment on this blog. As long as the comment content is not folded, you can participate in the lottery;
lottery method: the program automatically pulls the unfolded comments and randomly selects 3 partners, each person can comment up to 5 times; lottery
time: 2023-09-16 17:00;
The results are announced: The lottery is pending, and the winner will receive a physical book "Vue.js from Beginner to Master" (free shipping to your home)