Question

我是Javascript的新手，我遇到了一个词典列表问题。我有一个像这样的对象：

0:{Year: "2007", expenditure: "314,448.7", category: "Exports"}
1:{Year: "2008", expenditure: "320,805.2", category: "Exports"}
2:{Year: "2007", expenditure: "314,448.7", category: "Imports"}
3:{Year: "2008", expenditure: "320,805.2", category: "Imports"}

我希望将其转换为一个新的值，其中值Exports和Imports为两个不同的列，其下方的相应支出。像这样：

0:{Year: "2007", Exports: "314,448.7", Imports: "314,448.7"}
1:{Year: "2008", Exports: "320,805.2", Imports: "320,805.2"}

有谁知道怎么做？提前谢谢。

Answer 1

您可以使用array#reduce根据Year累积对象。然后使用Object.values()提取所有值。

＆＃13;

const arr = [{Year: "2007", expenditure: "314,448.7", category: "Exports"},{Year: "2008", expenditure: "320,805.2", category: "Exports"}, {Year: "2007", expenditure: "314,448.7", category: "Imports"},{Year: "2008", expenditure: "320,805.2", category: "Imports"}],
    result = Object.values(arr.reduce((r, {Year, expenditure, category}) => {
      r[Year] = r[Year] || {Year};
      r[Year][category] = expenditure;
      return r;
    },{}));
console.log(result);

＆＃13;

Answer 2

使用函数<div class="arrow_box"> <img src="https://upload.wikimedia.org/wikipedia/commons/3/30/Amazona_aestiva_-upper_body-8a_%281%29.jpg" class="user-image" alt=""> </div>根据类别累积。

＆＃13;

Arra.prototype.reduce

＆＃13;

const arr = [{Year: "2007", expenditure: "314,448.7", category: "Exports"},{Year: "2008", expenditure: "320,805.2", category: "Exports"}, {Year: "2007", expenditure: "314,448.7", category: "Imports"},{Year: "2008", expenditure: "320,805.2", category: "Imports"}];
const result = Object.values(arr.reduce((a, e) => ((a[e.Year] || (a[e.Year] = { Year: e.Year }))[e.category] = e.expenditure, a), {}));

console.log(result);

＆＃13;

将类别转换为列名称

2 个答案: