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：

(df.start.shift(-1)==df.end).shift().ne(True).cumsum()

Out[434]: 
0    1
1    1
2    1
3    2
4    2
5    2
dtype: int32

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", 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"}

有谁知道怎么做？提前谢谢。

Answer 1

这对reduce来说是个不错的选择：

＆＃13;

let arry = [{
    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"
  }
]

let result = arry.reduce((r, v) => r.concat([{
  Year: v.Year,
  [v.category]: v.expenditure
}]), [])

console.log(result)

＆＃13;

Answer 2

    const output = input.map(({Year, expenditure, category}) => ({Year, [category]: expenditure }));

只需破坏每个物体并构建一个新物体。您还可以使用rest / spread包含新对象中的所有其他属性：

 const output = input.map(({expenditure, category, ...rest}) => ({[category]: expenditure, ...rest }));

如何将分类值转换为列名

2 个答案: