Class Inheritance in JavaScript
From the JavaScript cheat sheet · Classes · verified Jul 2026
Class Inheritance
Extending classes with inheritance
javascript
// Class inheritance
class Animal {
constructor(name) {
this.name = name;
}
speak() {
return `${this.name} makes a sound`;
}
}
class Dog extends Animal {
constructor(name, breed) {
super(name); // call parent constructor
this.breed = breed;
}
bark() {
return 'Woof!';
}
}💡 super() must be called before using this in constructor
⚡ Use super.method() to call parent methods
📌 Private fields start with # and are truly private
🔥 Static methods are inherited but not instance methods