Question

我想从数组中的对象中删除每个属性，除了其中一些属性：

var listToKeep = ['name', 'school'];

var arrayOfObjects = [{id:'abc',name:'oh', school: 'a', sport: 'a'},
                      {id:'efg',name:'em', school: 'b', sport: 's'},
                      {id:'hij',name:'ge', school: 'c', sport: 'n'}]

我正在尝试这个，但这只是试图删除一个：

arrayOfObjects .forEach(function(v){ delete v.id});

预期结果将是：

var arrayOfObjects = [{name:'oh', school: 'a'},
                          {name:'em', school: 'b'},
                          {name:'ge', school: 'c'}]

我不想使用for loop。

Answer 1

您可以将数组中的每个项目映射到新项目，通过减少要保留的键列表来创建：

const newArray = arrayOfObjects.map(obj => listToKeep.reduce((newObj, key) => {
  newObj[key] = obj[key]
  return newObj
}, {}))

如果要改变原始对象并删除属性，可以使用两个forEach循环并删除运算符：

arrayOfObjects.forEach(obj => listToKeep.forEach((key) => {
  delete obj[key]
}, {}))

如果你可以使用lodash或类似的库，你可以选择对象的属性，例如：

const newArray = arrayOfObjects.map(obj => _.pick(obj, listToKeep))

Answer 2

您可以遍历arrayOfObjects数组中每个JSON对象的键，然后如果在数组listToKeep中找不到该键，则从该对象中删除该key:value。由于您要更改现有的arrayOfObjects，因此您可以按照此方法在对象属性上使用delete。

var listToKeep = ['name', 'school'];

var arrayOfObjects = [{id:'abc',name:'oh', school: 'a', sport: 'a'},
                      {id:'efg',name:'em', school: 'b', sport: 's'},
                      {id:'hij',name:'ge', school: 'c', sport:'n'}];
arrayOfObjects.forEach((obj)=>{
  Object.keys(obj).forEach((key)=>{
     if(listToKeep.indexOf(key) === -1){
       delete obj[key];
     }
  });
});
console.log(arrayOfObjects);

javascript在数组

2 个答案: