JAVASCRIPT

javascript generator function

function* idMaker() {
  var index = 0;
  while (true)
    yield index++;
}

var gen = idMaker();

console.log(gen.next().value); // 0
console.log(gen.next().value); // 1
console.log(gen.next().value); // 2
console.log(gen.next().value); // 3
// ...

generators in javascript

function* g(){    //or function *g(){}
  console.log("First");
  yield 1;
  console.log("second");
   yield 2;
  console.log("third");
} 
let generator=g();
generator.next();
generator.next();

generator function javascript

function* expandSpan(xStart, xLen, yStart, yLen) {
    const xEnd = xStart + xLen;
    const yEnd = yStart + yLen;
    for (let x = xStart; x < xEnd; ++x) {
         for (let y = yStart; y < yEnd; ++y) {
            yield {x, y};
        }
    }
} 


//this is code from my mario game I dont think this code is functional

generators in javascript

//- With a generator function, values are not evaluated 
//until they are needed.
//- Therefore a generator allows us to define a potentially
//infinite data structure.

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

const gen = generator(); // "Generator { }"

console.log(gen.next().value); // 1
console.log(gen.next().value); // 2
console.log(gen.next().value); // 3

generator js

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

var g = gen(); // "Generator { }"

Create JavaScript Generators

// define a generator function
function* generator_function() {
   ... .. ...
}

// creating a generator
const generator_obj = generator_function();

generator function in javascript

// generator function in javascript
// The function* declaration (function keyword followed by an asterisk) defines a generator function, which returns a Generator object.
function* generator(i) {
  yield i;
  yield i + 10;
}

const gen = generator(10);

console.log(gen.next().value);
// expected output: 10

console.log(gen.next().value);
// expected output: 20

console.log(gen.next().value);
// expected output: undefined

JavaScript — Generators

function* makeRangeIterator(start = 0, end = 100, step = 1) {
    let iterationCount = 0;
    for (let i = start; i < end; i += step) {
        iterationCount++;
        yield i;
    }
    return iterationCount;
}