JS Iterator + Generator

Iterator

//Iterator Example
function nameIterator(names) {
  let nextIndex = 0;

  return {
    next:function(){
      return nextIndex<names.length ?
      {value:names[nextIndex++],done:false} :
      {done:true};
    }
  }
  
}

//Create an array of names
const namesArray = ['Jack','Jill','John'];

//Init iterator and pass in the names array
const names = nameIterator(namesArray);

console.log(names)
console.log(names.next());
console.log(names.next());
console.log(names.next());
console.log(names.next());
console.log(names.next());

Generator

//Generator Example
function* sayNames(){   // * generator
  yield `Jack`;
  yield `Jill`;
  yield `John`;
}

const name = sayNames();

console.log(name.next());
console.log(name.next());
console.log(name.next());
console.log(name.next());

返回相同

Generator用作ID生成器

//ID Creator
function* craeteids(){
  let index=0;

  while(true){
    yield index++;
  }
}
const gen = craeteids();
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);