JavaScript Class Getters and Setters

Written by Swapnil RajaPublished 24 Aug 2026

Class getters and setters let a method be used like a plain property.

The syntax is the same as in an object literal, but it matters more here.

Paired with a private field, a getter is how a class controls access to its data.

Example

javascript

class Rectangle {
  constructor(width, height) {
    this.width = width;
    this.height = height;
  }

  get area() {
    return this.width * this.height;
  }
}

console.log(new Rectangle(4, 5).area);

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Example

javascript

class Rectangle {
  constructor(width, height) {
    this.width = width;
    this.height = height;
  }
  get area() {
    return this.width * this.height;
  }
}

const rect = new Rectangle(4, 5);
rect.width = 10;

console.log(rect.area);

Example

javascript

class Person {
  #age = 0;

  set age(value) {
    this.#age = value < 0 ? 0 : value;
  }

  get age() {
    return this.#age;
  }
}

const person = new Person();
person.age = -5;

console.log(person.age);

Example

javascript

class Person {
  constructor(first, last) {
    this.first = first;
    this.last = last;
  }

  get fullName() {
    return this.first + " " + this.last;
  }

  set fullName(value) {
    const parts = value.split(" ");
    this.first = parts[0];
    this.last = parts[1];
  }
}

const person = new Person("Ada", "Lovelace");
person.fullName = "Grace Hopper";

console.log(person.first + " / " + person.fullName);

Complete Example

html

<!DOCTYPE html>
<html>
<head>
  <title>JavaScript Class Getters and Setters</title>
</head>
<body>

  <h1>Class Getters and Setters</h1>

  <p id="out"></p>

  <script>
    class Temperature {
      #celsius = 0;

      get celsius() {
        return this.#celsius;
      }

      set celsius(value) {
        this.#celsius = value;
      }

      get fahrenheit() {
        return this.#celsius * 9 / 5 + 32;
      }

      set fahrenheit(value) {
        this.#celsius = (value - 32) * 5 / 9;
      }
    }

    const temp = new Temperature();
    temp.fahrenheit = 212;

    document.getElementById("out").textContent =
      temp.fahrenheit + "F is " + temp.celsius + "C";
  </script>

</body>
</html>

JavaScript Class Getters and Setters

Example

Getters and Setters in Classes

Syntax

A Computed Property

Example

Exposing a Private Field

Example

Validating in a Setter

Example

Splitting a Value

Example

Getters Are Inherited

Example

Complete Example

Try It Yourself

Important Points

Conclusion