根据javascript中的条件修改现有数组对象

Question

如何在javascript中修改数组对象，

obj1和obj2两个数组对象，其中title的键值相同， 然后在javascript中添加到键details。

如果obj1和obj2的标题相同，则在详细信息键中添加amt,idx，

function modifyArray(obj1, obj2){
   return obj1.map(a1=> {
          return {
            ...a1,
            details: obj2
              .filter(a2=> a2.title=== a1.title)
              .map(a2=> ({ idx: a2.idx, amt: a2.amt|| 0 }))
          }
        })
}

var obj1= [ 
  {id:1, title: "item1", details: [{idx:1, amt: 100},{idx:2, amt: 200}]} 
  {id:2, title: "item2", details: []},
  {id:3, title: "item3" } 
]

var obj2 =[
  { idx:"3", title: "item1", amt: 120},
  { idx:"4", title: "item1", amt: 140},
  { idx:"1", title: "item2", amt: 220},
  { idx:"1", title: "item3", amt: 240},
  { idx:"2", title: "item3", amt: 200}
]

预期输出：

 [ 
  {id:1, title: "item1", details: [{idx:1, amt: 100},{idx:2, amt: 200},{idx:3, amt: 120},{idx:4, amt: 140}]} 
  {id:2, title: "item2", details: [{idx:1, amt: 220}]},
  {id:3, title: "item3", details: [{idx:1, amt: 240},{idx:2, amt: 200}] } 
]

Answer 1

不确定。但试试这样的。

function comp(obj1, obj2) {
  const final = [];
  obj1.forEach((element1) => obj2.forEach((element2) => {
    if (element1.title == element2.title) {
      final.push({
        id: element1.id,
        title: element1.title,
        details: element1.details || []
      })
    }
  }))
  return final;
}

Answer 2

一种方法是通过合并两个数组来使用reduce。这里是：

var obj1= [{id:1, title: "item1", details: [{idx:1, amt: 100},{idx:2, amt: 200}]}, {id:2, title: "item2", details: []}, {id:3, title: "item3" }];

var obj2 =[ { idx:"3", title: "item1", amt: 120}, { idx:"4", title: "item1", amt: 140}, { idx:"1", title: "item2", amt: 220}, { idx:"1", title: "item3", amt: 240}, { idx:"2", title: "item3", amt: 200}];

var result = Object.values([...obj1,...obj2].reduce((acc, elem)=>{
    if(!elem.idx){
     acc[elem.title] = elem.details ? elem : {...elem, details:[]}
     } else {
     acc[elem.title].details.push({idx:elem.idx, amt:elem.amt});
    }
    return acc; 
},{}));

console.log(result);