javascript - 将数据分配给 for 中的对象

Question

我正在尝试将循环数据添加到对象中。

subItem.allAvgObj = {};

for(var i = 0; i < subItem.implementations.length; i++) {

if (subItem.implementations[i].avg_score) {

        Object.assign(subItem.allAvgObj, {
          scoreAvg: subItem.implementations[i].avg_score,
          scorePonderation: subItem.implementations[i].ponderation,
        })

    }
}

仅，只有循环的最后一个对象被分配。

{
 "scoreAvg": 8,
 "scorePonderation": 10
}

我尝试使用数组，它可以工作(但它是一个具有单个值的数组，但循环可以工作)

subItem.allAvgArray.push(subItem.implementations[i].avg_score);

返回:

[
  13.5,
  16,
  8
]

如何制作这样的对象？

{
  "scoreAvg": 13.5,
  "scorePonderation": 20
},
{
  "scoreAvg": 16,
  "scorePonderation": 20
},
{
  "scoreAvg": 8,
  "scorePonderation": 10
}

谢谢

Answer 1

创建对象数组的更简单方法可能是使用 .filter()删除那些没有 avg_score() 的内容，然后 .map()从每个项目创建结果对象。

let result = subItem.implementations
  .filter(i => i.avg_score)
  .map(i => ({
    scoreAvg: i.avg_score,
    scorePonderation: i.ponderation
  }));

const subItem = {
  implementations: [{
      avg_score: 15.7,
      ponderation: 20
    },
    {
      avg_score: 0,
      ponderation: 15
    }, {
      avg_score: 6.8,
      ponderation: 10
    }
  ]
}

let result = subItem.implementations
  .filter(i => i.avg_score)  //remove items without avg_score
  .map(i => ({               //turn the remaining items into objects
    scoreAvg: i.avg_score,
    scorePonderation: i.ponderation
  }));
  
console.log(result);

或者，reduce()一次性解决方案。

let result = subItem.implementations
  .reduce((acc,i) => 
    i.avg_score 
      ? [...acc, {scoreAvg: i.avg_score, scorePonderation: i.ponderation}] 
      : acc
  ,[]);

const subItem = {
  implementations: [{
      avg_score: 15.7,
      ponderation: 20
    },
    {
      avg_score: 0,
      ponderation: 15
    }, {
      avg_score: 6.8,
      ponderation: 10
    }
  ]
}

let result = subItem.implementations
  .reduce((acc,i) => 
    i.avg_score  //if avg_score, add an object. else, do nothing.
      ? [...acc, {scoreAvg: i.avg_score, scorePonderation: i.ponderation}] 
      : acc
  ,[]);

console.log(result);

请注意，reduce() 解决方案在性能上弥补了可读性方面的不足。