Question

我有这个（说它的对象A）

[{grade:1},{grade:2},{grade:3}]直到100日。

如何将这些现有数据（称其为对象B）映射到它们中？

[
{grade:1,name:'alice',address:{poscode:123},tel:324}
{grade:5,name:'wonder',address:{poscode:123},tel:1234223},
{grade:90,name:'james',address:{poscode:234},tel:324}]
]

表示50级，它不匹配任何对象B，最终结果也应该具有名称和地址属性，为它们赋值null以使数组保持一致。如果我使用对象A循环，那么问题是如果对象B中还有其他属性？

Answer 1

如果我正确理解了问题，您可以使用对象A作为地图源，然后使用Object.assign从对象B复制单个属性以及添加一些默认值：

＆＃13;

const objA = [{grade:1},{grade:2},{grade:3}];
const objB = [
{grade:1,name:'alice',address:{poscode:123},tel:324},
{grade:5,name:'wonder',address:{poscode:123},tel:1234223},
{grade:90,name:'james',address:{poscode:234},tel:324}
];
const objC = objA.map(rootObject => Object.assign(
    // A new object with some defaults
    { name: null, address: null, tel: null },
    // The source object from objA
    rootObject,
    // The data object from objB, if any
    objB.find(detail => detail.grade === rootObject.grade)
  )
);
console.log(objC);

＆＃13;

Answer 2

您可以使用方便的Array方法实现此目的。请参阅以下代码段：

＆＃13;

const a = [
  {grade: 1},
  {grade: 2},
  {grade: 3},
  {grade: 4},
  {grade: 5},
  {grade: 90},
  {grade: 100}
];
const b = [
  {grade:1,name:'alice',address:{poscode:123},tel:324},
  {grade:5,name:'wonder',address:{poscode:123},tel:1234223},
  {grade:90,name:'james',address:{poscode:234},tel:324}
];

let result = a.map(aItem => {
  let match = b.find( bItem => aItem.grade === bItem.grade );
  if(!match){
    return Object.assign({}, aItem, { name: null, address: {}, tel: null });
  } else {
    return match;
  }
});
console.log(result);

＆＃13;

按属性映射对象数组

2 个答案: