将Array of Objects中的空值替换为以前填充的值

Question

我有一个对象数组，对象的一些值是空的，我想用前一个对象的值替换它们，下面是一个示例：

[
  {
    name: "Mark",
    surname: "Something",
  },
  {
    name: "",
    surname: "",
  },
  {
    name: "Richard",
    surname: "SomeSurname",
  },
  {
    name: "",
    surname: "",
  },
];

我的目标是用以前的值替换空值：

[
  {
    name: "Mark",
    surname: "Something",
  },
  {
    name: "Mark",
    surname: "Something",
  },
  {
    name: "Richard",
    surname: "SomeSurname",
  },
  {
    name: "Richard",
    surname: "SomeSurname",
  },
];

Answer 1

​

const a = [
  {
    name: "Mark",
    surname: "Something"
  },{
    name: "",
    surname: "" 
  },{
    name: "Richard",
    surname: "SomeSurname"
  },{
    name: "",
    surname: ""
  }
];
for (let i = 0; i < Math.trunc(a.length / 2); ++i) {
  a[2 * i + 1].name = a[2 * i].name;
  a[2 * i + 1].surname = a[2 * i].surname;
}
console.log(a);

​

Answer 2

​

const array = [
  {
    name: "Mark",
    surname: "Something",
  },
  {
    name: "",
    surname: "",
  },
  {
    name: "Richard",
    surname: "SomeSurname",
  },
  {
    name: "",
    surname: "",
  },
];

//create new array with map es6
let newArray = array.map( (obj,index) => { 
  if( !obj.name && !obj.surname ){
    //if values are empty, create a new one with the previous index
    return { name: array[index-1].name, surname: array[index-1].surname }
  }
  //else return original value
  return obj
})

console.log( newArray );

​

Answer 3

我会遍历列表并保存最后一个非空对象os的索引，然后当我遇到一个空对象时更新它的值：

​

const list = [
  {
    name: "Mark",
    surname: "Something",
  },
  {
    name: "",
    surname: "",
  },
  {
    name: "Richard",
    surname: "SomeSurname",
  },
  {
    name: "",
    surname: "",
  },
];

let emptyIndex = 0;
for (let i = 0; i < list.length; ++i) {
  if (list[i].name) {
    fullIndex = i;
  } else {
    list[i].name = list[fullIndex].name;
    list[i].surname = list[fullIndex].surname;
  }
}

console.log(list);

​