How do I use generics in classes in TypeScript?

How do I use generics in classes in TypeScript?

You can define a class with a generic type by using angle brackets. For example, class Box<T> {} allows you to create a box that can hold any type.

Can you give me an example of a generic class?

Sure! Here's a simple example:

class Box<T> {
    private content: T;

    constructor(value: T) {
        this.content = value;
    }

    getContent(): T {
        return this.content;
    }
}

const numberBox = new Box<number>(123);
console.log(numberBox.getContent()); // 123

What if I want to restrict the type to only certain types?

You can use constraints with generics. For example, class Box<T extends Number> restricts T to be a subtype of Number.

Can generics be used with interfaces as well?

Yes, generics can be used with interfaces. You can define a generic interface like this:

interface Pair<K, V> {
    key: K;
    value: V;
}