How do I use private properties in JavaScript classes?

How do I use private properties in JavaScript classes?

In JavaScript, you can use the # symbol to define private properties in classes. For example:

class MyClass {
    #privateProperty;

    constructor(value) {
        this.#privateProperty = value;
    }

    getPrivateProperty() {
        return this.#privateProperty;
    }
}

This way, #privateProperty is only accessible within the class.

Can you give me an example of accessing a private property?

Sure! Here's how you can access a private property using a method:

const myInstance = new MyClass('Hello');
console.log(myInstance.getPrivateProperty()); // Outputs: Hello

You cannot access #privateProperty directly from outside the class.

What happens if I try to access it directly?

If you try to access a private property directly, like this:

console.log(myInstance.#privateProperty);

You'll get a syntax error because private properties are not accessible outside their class.

Are there any alternatives to private properties?

Yes, you can use closures or WeakMaps to achieve similar encapsulation, but private fields with # are the most straightforward in modern JavaScript.