Generators

In JavaScript, generators are special functions that can be paused and resumed during their execution. They allow you to define an iterative algorithm by writing a function that can yield multiple values over time, instead of returning a single value. Generators provide a powerful way to work with sequences of data.

To define a generator function, you use the function* syntax. Inside the generator function, you can use the yield keyword to produce a value and temporarily pause the execution. Here’s an example to demonstrate how generators work:

function* numberGenerator() {   yield 1;   yield 2;   yield 3; }

const generator = numberGenerator();  

console.log(generator.next().value);
// Output: 1 
console.log(generator.next().value);
// Output: 2 
console.log(generator.next().value);
// Output: 3 
console.log(generator.next().value); 
// Output: undefined

function* squareGenerator() {
	const number = yield 'Provide a number: ';   
	yield number * number; 
}  

const square = squareGenerator(); console.log(square.next().value); 
// Output: Provide a number: 
console.log(square.next(5).value); 
// Output: 25

When should we use generators

• one can choose to jump out of a function and let outer code to determine when to jump back into the function.
• the control of asynchronous call can be done outside of your code