What are JS Generators?
Generators are a feature in Javascript which are basically functions that are kind of like iterators.
Creating
You can create generators like this:
function* myGenerator() {}
The *
after function
is required.
Yielding
The core mechanic of generators is yield
ing values.
function* myGenerator() {
yield 1;
yield "foo";
yield "bar";
yield { thing: true };
}
Taking Values
You have created your generator. Now, we need to use it. When you have a generator, you can call .next()
on it, and it will run the generator until it reaches a yield
statement. When it reaches it, it will return an object with two parameters, value
, and done
.
const one = myGenerator.next().value; // 1
const foo = myGenerator.next().value; // "foo"
const bar = myGenerator.next().value; // "bar"
const thingTrue = myGenerator.next().value; // { thing: true }
MDN Docs
You can look more into generators on the MDN docs.