如何按值而不是键对 Map 对象数据进行排序？

Question

我想看看是否有一种方法可以不按键 (app.id) 而是按值 (app.description) 对 Map 对象数据进行排序。 例如，我有使用以下代码输入的以下数据：

let newMap = new Map();
_.forEach(this.props.applicationTypes.APPLICATION_TYPE, (appType) => {
  newMap.set(appType.id, appType.description);
});
this.setState({applicationTpeMap: newMap});

[[Entries]]
  0: {234 => "Technical Assistance"}
  1: {235 => "Initiative Project"}
  2: {236 => "Project scoping"}
  3: {231 => "Plan"}
  4: {232 => "Project"}
  5: {233 => "Management Cost"}

我可以使用 javascript 的 sort 方法对这些数据进行排序，但它根据 id 对数据进行排序，如下所示：

let newMap = new Map();
_.forEach(this.props.applicationTypes.APPLICATION_TYPE, (appType) => {
  newMap.set(appType.id, appType.description);
});
const mapAsc = new Map([...newMap.entries()].sort());
this.setState({applicationTpeMap: mapAsc});

[[Entries]]
  0: {231 => "Plan"}
  1: {232 => "Project"}
  2: {233 => "Management Cost"}
  3: {234 => "Technical Assistance"}
  4: {235 => "Initiative Project"}
  5: {236 => "Project scoping"}

我正在寻找的是这样的东西，其中数据按描述排序，如下所示：

期望的输出：

[[Entries]]
0: {235 => "Initiative Project"}
1: {233 => "Management Cost"}
2: {231 => "Plan"}
3: {232 => "Project"}
4: {236 => "Project scoping"}
5: {234 => "Technical Assistance"}

Answer 1

您可以使用entries()并对该数组进行排序并生成一个新的map 。

 let newMap = new Map(); newMap.set(234, "Technical Assistance"); newMap.set(235, "Initiative Project"); newMap.set(236, "Project scoping"); newMap.set(231, "Plan"); newMap.set(232, "Project"); newMap.set(233, "Management Cost"); const sorted = new Map([...newMap.entries()].sort((a, b) => a[1].localeCompare(b[1]))); console.log([...sorted.entries()]);

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