Summary of feasible ways to create objects in JavaScript

Preface

In web front-end development, JavaScript is a powerful language, and one of its core is the creation and operation of objects. Objects are an important part of data structures in JavaScript. Flexible creation and use of objects can help developers build complex applications. This article will explore in-depth various methods of creating objects in JavaScript, and provide detailed explanations based on code examples and actual development experience.

1. Basic concept: the role and significance of objects

1.1 Basic definition of objects

In JavaScript, an object is a data structure that stores key-value pairs. Each key is a string or Symbol type identifier, and the corresponding value can be any data type, including functions (i.e. methods).

Example 1: Simple object definition

// Create a simple objectconst person = {
  name: "Alice", // Attributes  age: 25,       // Attributes  greet: function() { // method    (`Hello, my name is ${}`);
  }
};

(); // Output: Hello, my name is Alice

1.2 The role of the object

Objects are widely used in JavaScript and are often used to represent entities in the real world, encapsulate data and behaviors, and pass them as function parameters or return values.

2. Methods for creating objects

2.1 Using Object Literals

Object literals are the most common and easiest way to go directly through braces{}Define the object.

Example 2: Use of Object Literals

// Create an object using object literalconst book = {
  title: "JavaScript Advanced Programming",
  author: "Nicholas C. Zakas",
  getDetails: function() {
    return `${} by ${}`;
  }
};

(()); // Output: JavaScript Advanced Programming by Nicholas C. Zakas

advantage: Concise syntax, suitable for quickly defining small objects.
shortcoming: The same structure cannot be reused to create multiple similar objects.

2.2 Using constructors

The constructor is a classic object-oriented programming method that allows us to passnewKeyword creates an object instance.

Example 3: Use of constructors

// Define the constructorfunction Car(brand, color) {
   = brand; // Attributes   = color; // Attributes   = function() { // method    (`${} car started`);
  };
}

// Create an instanceconst myCar = new Car("Toyota", "Red");
(); // Output: Toyota car started

advantage: Supports object reuse, which facilitates the creation of objects with the same structure.
shortcoming: The method is redefined every time an instance is created, wasting memory.

2.3 Using prototype inheritance

Through the prototype chain, we can optimize the method definition of the constructor to avoid repeated creation.

Example 4: Use of prototype inheritance

// Define the constructorfunction Animal(name) {
   = name;
}

// Define the method on the prototype = function() {
  (`${} makes a sound.`);
};

// Create an instanceconst dog = new Animal("Dog");
(); // Output: Dog makes a sound.

advantage: Methods on the prototype shared by all instances, saving memory.
shortcoming: Modifying the prototype will affect all instances.

2.4 Use

Methods allow us to create new objects by specifying prototype objects, which is very suitable for implementing prototype-based inheritance.

Example 5: Use

// Define the prototype objectconst animalPrototype = {
  speak: function() {
    (`${} makes a sound.`);
  }
};

// Create an object usingconst cat = (animalPrototype);
 = "Cat";
(); // Output: Cat makes a sound.

advantage: Explicitly specify prototype objects, with high flexibility.
shortcoming: The grammar is a bit complicated and may not be easy for beginners to understand.

2.5 Use Class (ES6)

ES6 has introducedclassSyntactic sugar makes prototype-based inheritance more intuitive and easy to read.

Example 6: Use of classes

// Define the classclass Person {
  constructor(name, age) {
     = name;
     = age;
  }

  greet() {
    (`Hello, my name is ${}`);
  }
}

// Create an instanceconst alice = new Person("Alice", 25);
(); // Output: Hello, my name is Alice

advantage: Clear syntax, easy to understand and maintain.
shortcoming: In essence, it is still based on prototype inheritance, and you need to understand the underlying mechanism.

3. Ideas for using functions of different methods

3.1 Creation of simple objects

For single-use simple objects, it is recommended to use object literals. It is syntaxy and is suitable for quickly defining small data structures.

Example 7: Use object literal storage configuration

const config = {
  debugMode: true,
  maxConnections: 100,
  timeout: 5000
};

3.2 Creation of complex objects

When you need to create multiple objects with the same structure, it is recommended to use constructors or classes. This method can improve the maintainability and reusability of the code.

Example 8: Use classes to manage user data

class User {
  constructor(id, username, email) {
     = id;
     = username;
     = email;
  }

  displayInfo() {
    (`User ID: ${}, Username: ${}, Email: ${}`);
  }
}

const user1 = new User(1, "alice", "alice@");
(); // Output: User ID: 1, Username: alice, Email: alice@

3.3 Application of prototype inheritance

Prototype inheritance is a good choice when sharing methods or attributes are needed. It can effectively reduce memory usage.

Example 9: Prototype inheritance of shared methods

function Product(name, price) {
   = name;
   = price;
}

 = function(amount) {
   -= amount;
  (`${} is now priced at $${}`);
};

const product = new Product("Laptop", 1000);
(100); // Output: Laptop is now priced at $900

3.4 Creation of dynamic objects

In some scenarios, we need to create objects dynamically based on runtime conditions. At this time, it can be combined with factory model or other advanced technologies.

Example 10: Dynamic creation of objects in factory mode

function createVehicle(type, brand) {
  const vehicle = {};
  if (type === "car") {
     = "Car";
     = function() {
      (`${brand} car is driving.`);
    };
  } else if (type === "bike") {
     = "Bike";
     = function() {
      (`${brand} bike is riding.`);
    };
  }
  return vehicle;
}

const car = createVehicle("car", "Toyota");
(); // Output: Toyota car is driving.
const bike = createVehicle("bike", "Honda");
(); // Output: Honda bike is riding.

4. Techniques and best practices in actual development

4.1 Avoid direct modification of prototypes

Directly modify the prototype of the built-in object (such as) may lead to unexpected behavior and should be avoided as much as possible.

4.2 Use the protection object

In some cases, we want the content of the object to be immutable. Can be usedMethod freeze it.

Example 11: Freeze the object

const constants = ({
  PI: 3.14159,
  E: 2.71828
});

 = 3; // Will not take effect(); // Output: 3.14159

4.3 Modular management of objects

In large projects, it is recommended to encapsulate object definitions into modules to improve the organization and maintainability of the code.

As a web front-end developer, mastering the creation methods and application scenarios of objects in actual work can significantly improve development efficiency and code quality.

This is the end of this article about the feasible methods of creating objects in JavaScript. For more information about feasible methods of creating objects in JavaScript, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!