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javascript - 为什么我的数组的顺序在 for 循环中保持变化

问题描述

我正在运行以下代码（我很欣赏有一些重复，需要整理）：

async function translateRequests(nameOfRequestsArray) {
  document.body.style.cursor = "wait";
  for (let i = 0; i < nameOfRequestsArray.length; i++) {
    //see if nameOfRequestsArray[i] has been translated already and if it has then skip it!
    if (nameOfRequestsArray[i].lastUpdated.length != 3) {
    //translate requesters
    let a = users.map(function(search) { return search.id; }).indexOf(nameOfRequestsArray[i].requester);
    nameOfRequestsArray[i].requesterFirstName = users[a].firstName;
    nameOfRequestsArray[i].requesterSurname = users[a].surname;
    //translate requestees
    console.log(nameOfRequestsArray[i]);
    console.log('i1: ' + i);
    if (nameOfRequestsArray[i].type == 'user') {
      let b = users.map(function(search) { return search.id; }).indexOf(nameOfRequestsArray[i].requestee);
      nameOfRequestsArray[i].requesteeFirstName = users[b].firstName;
      nameOfRequestsArray[i].requesteeSurname = users[b].surname;
    } else if (nameOfRequestsArray[i].type == 'team') {
      //get teams if they haven't already been downloaded
      if (teams.length == 0) {
        //get teams
        data = JSON.stringify({"active": true});
        teams = await makeRequest("POST", "http://127.0.0.1:7071/retrieveteams", data);
        console.log(JSON.stringify(teams), nameOfRequestsArray[i].requestee)
      }
      console.log(nameOfRequestsArray[i]);
      console.log('i2: ' + i);
      let d = teams.map(function(search) { return search.id; }).indexOf(nameOfRequestsArray[i].requestee);
      nameOfRequestsArray[i].requesteeFirstName = teams[d].teamName;
    }
    //translate categories
    let c = categories.map(function(search) { return search.id; }).indexOf(nameOfRequestsArray[i].categoryId);
    nameOfRequestsArray[i].categoryName = categories[c].name;
    //split up lastUpdated dates
    let z = Date.parse(nameOfRequestsArray[i].lastUpdated) - timezoneOffset;
    z = new Date(z).toISOString();
    nameOfRequestsArray[i].lastUpdated = z.replace('Z','').split('T');
    nameOfRequestsArray[i].lastUpdated[2] = nameOfRequestsArray[i].lastUpdated[0].split('-').reverse().join('-');
    z = nameOfRequestsArray[i].lastUpdated[2].split('-');
    z[1] = z[1].replace('01','Jan');
    z[1] = z[1].replace('02','Feb');
    z[1] = z[1].replace('03','Mar');
    z[1] = z[1].replace('04','Apr');
    z[1] = z[1].replace('05','May');
    z[1] = z[1].replace('06','Jun');
    z[1] = z[1].replace('07','Jul');
    z[1] = z[1].replace('08','Aug');
    z[1] = z[1].replace('09','Sep');
    z[1] = z[1].replace('10','Oct');
    z[1] = z[1].replace('11','Nov');
    z[1] = z[1].replace('12','Dec');
    nameOfRequestsArray[i].lastUpdated[2] = z.join('-');
    //translate updates
    for (let x in nameOfRequestsArray[i].updates) {
      let d = users.map(function(search) { return search.id; }).indexOf(nameOfRequestsArray[i].updates[x].author);
      nameOfRequestsArray[i].updates[x].authorFirstName = users[d].firstName;
      nameOfRequestsArray[i].updates[x].authorSurname = users[d].surname;
      //translate the update dates
      let y = Date.parse(nameOfRequestsArray[i].updates[x].date) - timezoneOffset;
      y = new Date(y).toISOString();
      nameOfRequestsArray[i].updates[x].date = y.replace('Z','').split('T');
      nameOfRequestsArray[i].updates[x].date[0] = nameOfRequestsArray[i].updates[x].date[0].split('-').reverse().join('-');
      y = nameOfRequestsArray[i].updates[x].date[0].split('-');
      y[1] = y[1].replace('01','Jan');
      y[1] = y[1].replace('02','Feb');
      y[1] = y[1].replace('03','Mar');
      y[1] = y[1].replace('04','Apr');
      y[1] = y[1].replace('05','May');
      y[1] = y[1].replace('06','Jun');
      y[1] = y[1].replace('07','Jul');
      y[1] = y[1].replace('08','Aug');
      y[1] = y[1].replace('09','Sep');
      y[1] = y[1].replace('10','Oct');
      y[1] = y[1].replace('11','Nov');
      y[1] = y[1].replace('12','Dec');
      nameOfRequestsArray[i].updates[x].date[2] = y.join('-');
    }
    }
  }
  document.body.style.cursor = "initial";
}

这会在控制台中输出以下内容：

{type: "team", requester: "2f3e7466-28c7-1c90-cfaf-3dc8370d5dd3", requestee: "88edea02-f145-d79f-f077-e2b6a5db8972", categoryId: "2cb42736-f243-dacb-9961-9e007dc51f29", priority: 1, …}
javascript.js:135 i1: 26
javascript.js:208 type: undefined
javascript.js:146 [{"teamName":"Alpha 1","id":"88edea02-f145-d79f-f077-e2b6a5db8972"}] 2f3e7466-28c7-1c90-cfaf-3dc8370d5dd3
javascript.js:148 {type: "user", requester: "2f3e7466-28c7-1c90-cfaf-3dc8370d5dd3", requestee: "2f3e7466-28c7-1c90-cfaf-3dc8370d5dd3", categoryId: "2cb42736-f243-dacb-9961-9e007dc51f29", priority: 2, …}
javascript.js:149 i2: 26

如您所见（请参阅 requestee 和 priority 属性），当它到达 nameOfRequestsArray[26] 时，即使 i 仍然 = 26，数组的顺序似乎也在发生变化。我认为数组的意义在于，除非您通过执行 .sort 或 .reverse 显式更改顺序，里面的数据保持相同的顺序？这导致了我以前没有遇到过的执行问题。

标签： javascript

解决方案

由于 translateRequests 是一个异步函数，调用它的函数应该在调用下一个函数之前等待它的完成（在我的情况下，是对数组进行排序的函数），这就是数组内容移动的原因

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