Question

在下面的示例中，很容易理解生成器函数中的“ yield”。但是显然还有另一种“收益*”

function * loop(times){
   while(times){
     times--;
     yield times;
   }
}

let result = loop(2);
result.next() // {value: 1, done:false}

有人可以解释'yield'和'yield *'之间的区别吗？

Answer 1

yield*运算符将迭代委托给另一个可迭代的迭代器，如下所示：

// this function is more or less a no-op
function * iterate (iterable) {
  yield * iterable;
}

function * loop (times) {
   while (times) {
     times--;
     yield times;
   }
}

console.log('accepts iterables');
for (const value of iterate([1, 2, 3])) {
  console.log(value);
}

console.log('accepts generator iterators');
for (const value of iterate(loop(3))) {
  console.log(value);
}

const iterator = [1, 2, 3][Symbol.iterator]();

// skip first value
iterator.next();

console.log('accepts partially consumed iterators');
for (const value of iterate(iterator)) {
  console.log(value);
}

产量*和产量之间的差异

1 个答案: