Blueprints for objects, inheritance and getters.
✍️ 3 exercises + code challenge in this lessonA class is a template for creating objects.
constructor() runs when a new object is created with new.extends creates a child class; super() calls the parent constructor.get / set define computed properties.static methods belong to the class itself, not to instances.# are private.Mastering JavaScript Classes helps you write clean and reliable JavaScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
<pre id="out"></pre>
<script>
const log = (...a) => document.getElementById("out").textContent += a.join(" ") + "\n";
class Account {
#balance = 0;
constructor(owner) { this.owner = owner; }
deposit(amount) { this.#balance += amount; return this; }
get balance() { return this.#balance; }
static bank() { return "CodesInTech Bank"; }
}
class SavingsAccount extends Account {
constructor(owner, rate) {
super(owner);
this.rate = rate;
}
interest() { return this.balance * this.rate; }
}
const acc = new SavingsAccount("Ali", 0.05);
acc.deposit(10000).deposit(5000);
log(Account.bank(), "|", acc.owner, "has", acc.balance);
log("Yearly interest:", acc.interest());
</script>Check what you learned in “JavaScript Classes”.
Create a child class.
class Dog Animal { }
Which method runs when a new object is created from a class?
Create a class Person with a constructor(name) and a method greet() that returns "Hi, " + name. Log new Person("Ali").greet().
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