JavaScriptda iteratorlarning bir marta ishlashi

Har bir iterator siklda faqat bir marta qatnasha oladi. Bu biroz kutilmagan, lemin mantiqan - chaki bosib o'tilgan iterator o'zining done ni false ga o'rnatadi, shuning uchun u endi qayta takrorlanishi mumkin emas.

Keling, bunga ishonch hosil qilaylik. Quyidagi generatorimiz bor deb faraz qilaylik:

javascriptfunction *func() {
  yield 1;
  yield 2;
  yield 3;
}

Keling, iterator yaratamiz:

javascriptlet iter = func();

Keling, iteratorni bitta sikl bilan aylantiramiz:

javascriptfor (let elem of iter) {
  console.log(elem); // 1, 2, 3
}

Endi keling, iteratorni ikki ta sikl bilan aylantiramiz:

javascriptfor (let elem of iter) {
  console.log(elem); // 1, 2, 3
}
for (let elem of iter) {
  console.log(elem); // ishlamaydi
}

Muammoni hal qilish uchun har bir yangi sikl uchun o'z iteratoringizni yaratishingiz kerak:

javascriptlet iter1 = func();
for (let elem of iter1) {
  console.log(elem); // 1, 2, 3
}

let iter2 = func();
for (let elem of iter2) {
  console.log(elem); // 1, 2, 3
}

Biz soddalashtirishimiz mumkin:

javascriptfor (let elem of func()) {
  console.log(elem); // 1, 2, 3
}

for (let elem of func()) {
  console.log(elem); // 1, 2, 3
}

javascriptfunction *func() {
  for (let i = 1; i <= 3; i++) {
    yield i;
  }
}

let elems = func();

for (let elem of elems) {
  console.log(elem);
}
for (let elem of elems) {
  console.log(elem);
}