Generators are functions that can pause and resume their execution, allowing for more flexible control flow in JavaScript. They are created using the function* syntax and the yield keyword.
Here is an example of using a generator to generate a sequence of Fibonacci numbers:
function* fibonacci() {
let [prev, curr] = [0, 1];
while (true) {
[prev, curr] = [curr, prev + curr];
yield curr;
}
}
const fib = fibonacci();
console.log(fib.next().value); // 1
console.log(fib.next().value); // 2
console.log(fib.next().value); // 3
console.log(fib.next().value); // 5
In this example, we create a generator function fibonacci that generates an infinite sequence of Fibonacci numbers using the yield keyword. We then create a generator object fib from this function and use the .next() method to retrieve each successive value.