Generator

Generator_Iterator.js

function *foo(x) {
    console.log('x is ' + x);
    const y = yield (x + 1);
    console.log('y is ' + y);
    var z = yield (y + 2);
    console.log('z is '+ z);
    return (x + y + z);
}

var it = foo( 5 );

// note: not sending anything into `next()` here
// console.log( it.next() );       // { value:6, done:false }
// console.log( it.next( 12 ) );   // { value:8, done:false }
// console.log( it.next( 13 ) );   // { value:42, done:true }
const a = it.next().value;
console.log('1st result '+ a);
const b = it.next(a*2).value;
console.log('2nd result '+ b);
const c = it.next(b/2).value;
console.log('3rd result ' + c);


// outbut

// "x is 5"
// "1st result 6"
// "y is 12"
// "2nd result 14"
// "z is 7"
// "3rd result 24"