调用[Symbol.iterator]（）时不生成对象 [英] Object is not being produced on calling [Symbol.iterator]()

问题描述

这是源代码：

const james = {
    name: 'James',
    height: `5'10"`,
    weight: 185,
    [Symbol.iterator]:function*(){
    yield Object.keys(this) ;   
    }
};
const iterator = james[Symbol.iterator]();
//
console.log(iterator.next().value); // 'James'
console.log(iterator.next().value); // `5'10`
console.log(iterator.next().value); // 185

第一次调用 iterator.next（）。value 应该是打印

{"value":"James","key":"name","done":false}

但它正在打印 {value：[name，height ，weight]，done：false} 。如何解决这个问题？

but it is printing {"value":["name","height","weight"],"done":false}. How to resolve this?

推荐答案

您产生一次性所有密钥。意味着您的第一个 next 完成所有工作。您所需要的只是迭代密钥和 yield seq中的它们uns。

You yield all keys at once. Means that your first next do all work. All you need is to iterate over the keys and yield them in sequence.

const james = {
    name: 'James',
    height: `5'10"`,
    weight: 185,
    [Symbol.iterator]:function*(){   
       for(let key of Object.keys(this)) {
          yield  { propValue: this[key], propName: key};       
       }       
    }
};

const iterator = james[Symbol.iterator]();

console.log(iterator.next());
console.log(iterator.next());
console.log(iterator.next());

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