Learn Adding Methods to Classes | ES6 Class Fundamentals

When you define a method inside a JavaScript class, you are creating an instance method. This means every object created from that class will have access to the method, but the method itself is shared by all instances rather than being duplicated for each one. Defining methods in the class body (outside the constructor) attaches them to the class's prototype. This makes your code more efficient, since only one copy of the method exists in memory, regardless of how many objects you create from the class.

To add a method, simply write its name followed by parentheses and a code block within the class definition—there is no need for the function keyword. These methods can access the instance's properties using the this keyword.


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class Person {
  constructor(name) {
    this.name = name;
  }

  greet() {
    return "Hello, my name is " + this.name + "!";
  }
}

const alice = new Person("Alice");
console.log(alice.greet()); // Output: Hello, my name is Alice!

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Section 1. Chapter 5

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              123456789101112
            
class Person {
  constructor(name) {
    this.name = name;
  }

  greet() {
    return "Hello, my name is " + this.name + "!";
  }
}

const alice = new Person("Alice");
console.log(alice.greet()); // Output: Hello, my name is Alice!

Everything was clear?

Thanks for your feedback!

Section 1. Chapter 5