javascript - 根据以下数据创建自定义对象

Question

嗨，我正在尝试从对象数组和其他对象中为海关最终对象创建一个对象(代码中的示例)。我尝试在数组上执行 forEach 并创建一个新对象并将其推送到最终数组，但没有成功。 snapObj 中的数字可能不是 dataArr 中对象中的第一个数字(digit0 可能是 digital1...)，这使我很难找到正确的数字一并根据需要表示。有什么建议吗？

var dataArr = {};

//First array of objects
var arrayContactsWithNames = [{
  "digits0": "5555648583",
  "digits1": "4155553695",
  "name": "Kate Bell",
}, {
 "digits0": "5554787672",
 "digits1": "4085555270",
 "digits2": "4085553514",
 "name": "Daniel Higgins Jr.",
}, {
  "digits0": "8885555512",
  "digits1": "8885551212",
  "name": "John Appleseed",
}, {
  "digits0": "5555228243",
  "name": "Anna Haro",
}, {
  "digits0": "5557664823",
  "digits1": "7075551854",
  "name": "Hank M. Zakroff",
}, {
 "digits0": "5556106679",
 "name": "David Taylor",
}];

// Second object
var snapObj = {
  "5556106679": "test 1",
  "7075551854": "test 2",
  "8885551212": "test 1"
};


/* This is what I want to get:

var dataArr = [{
  "test 1": {
    "5556106679": "David Taylor",
    "8885551212": "John Appleseed"
  }
}, {
  "test 2": Object {
    "7075551854": "Hank M. Zakroff",
  }
}]
*/


// This is what I tried
arrayContactsWithNames.forEach((i) => {
  if (i in snapObject) {
     const newObj = Object.assign({snapObject[i],{ name },{digits${i}}});
     dataArr.push(newObj);
  }
});

     
    

Answer 1

逻辑是首先创建一个 number:name 形式的对象字典，并使用它来查找第二个对象。这是最优的，因为在对象中查找键只需要 O(1)。

var arrayContactsWithNames = [{
  "digits0": "5555648583",
  "digits1": "4155553695",
  "name": "Kate Bell",
}, {
 "digits0": "5554787672",
 "digits1": "4085555270",
 "digits2": "4085553514",
 "name": "Daniel Higgins Jr.",
}, {
  "digits0": "8885555512",
  "digits1": "8885551212",
  "name": "John Appleseed",
}, {
  "digits0": "5555228243",
  "name": "Anna Haro",
}, {
  "digits0": "5557664823",
  "digits1": "7075551854",
  "name": "Hank M. Zakroff",
}, {
 "digits0": "5556106679",
 "name": "David Taylor",
}];

var snapObj = {
  "5556106679": "test 1",
  "7075551854": "test 2",
  "8885551212": "test 1"
};

let parsedArr = arrayContactsWithNames.reduce((acc,{name,...digits}) => {
  Object.values(digits).forEach(digit => { acc[digit] = name });
  return acc;
}, {});  // create a { number : name } mapping with some es6 magic. Refer Object destructuring and spread operator to know how the digit0,digit1 etc are extracted. 
// console.log(parsedArr) 

let parsedObj = Object.keys(snapObj).reduce((acc,num) => { 
  let val = snapObj[num]
  if(!acc[val])
    acc[val] = {}
  acc[val][num] = parsedArr[num]; // use the lookup object with the number
  return acc;
},{}); // A simple reducer to create a new object in the desired shape.

console.log(parsedObj);