Advanced Generator Functions

We went over generator functions in the last blog post. Now is the time to go over some edge cases and advanced topics for generators.

Generators can be object properties

const objectWithGenerator = {
    *numberGenerator() {
        yield "1";
        yield "2";
    }
}

const numbers = objectWithGenerator.numberGenerator();

console.log(numbers.next()); // { value: '1', done: false }
console.log(numbers.next()); // { value: '2', done: false }
console.log(numbers.next()); // { value: undefined, done: true }

Generators can be class methods

class classWithGenerator {
    *numberGenerator() {
        yield "1";
        yield "2";
    }
}

const generatorObject = new classWithGenerator;
const numbers = generatorObject.numberGenerator();

console.log(numbers.next()); // { value: '1', done: false }
console.log(numbers.next()); // { value: '2', done: false }
console.log(numbers.next()); // { value: undefined, done: true }

Generators can be defined as expressions!

const objectWithGenerator = function* () {
    yield "1";
    yield "2";
}

const numbers = objectWithGenerator();

console.log(numbers.next()); // { value: '1', done: false }
console.log(numbers.next()); // { value: '2', done: false }
console.log(numbers.next()); // { value: undefined, done: true }

Generators are not constructors

const objectWithGenerator = {
    *numberGenerator() {
        yield "1";
        yield "2";
    }
}

const numbers = new objectWithGenerator(); // objectWithGenerator is not a constructor