按两个条件对数据进行排序? [英] Sorting data by two conditions?

问题描述

我有一个JSON对象，我想按时间和用户名的字母顺序对其进行排序:

I have a JSON object and I'm trying to sort it by both time and username alphabetically:

样本数据:

   const obj = [ {"timestamp": 1487184625, "user": "Eric", "action": "navigate"},
    {"timestamp": 1487184655, "user": "Bill", "action": "browse"},
    {"timestamp": 1487184685, "user": "Eric", "action": "key press"},
    {"timestamp": 1487184715, "user": "John", "action": "idle"},
    {"timestamp": 1487184755, "user": "Tran", "action": "search"},
    {"timestamp": 1487098049, "user": "Tran", "action": "click"},
    {"timestamp": 1487098079, "user": "Eric", "action": "click"},
    {"timestamp": 1487098109, "user": "Tran", "action": "click"},
    {"timestamp": 1487098139, "user": "Bill", "action": "navigate"},
    {"timestamp": 1487184625, "user": "Eric", "action": "navigate"},
    {"timestamp": 1487184655, "user": "Bill", "action": "browse"},
    {"timestamp": 1487184685, "user": "Eric", "action": "key press"},
    {"timestamp": 1487184715, "user": "John", "action": "idle"},
    {"timestamp": 1487184755, "user": "Tran", "action": "search"},
    {"timestamp": 1487098049, "user": "Tran", "action": "click"},
    {"timestamp": 1487098079, "user": "Eric", "action": "click"},
    {"timestamp": 1487098109, "user": "Tran", "action": "click"},
    {"timestamp": 1487098139, "user": "Bill", "action": "navigate"}]

我尝试过这样的事情:

console.log(obj.sort((a,b) => {
  // if(a.user.localeCompare(b.user)){
  //   return 1
  // }
  // if(!a.user.localeCompare(b.user)){
  //   return -1
  // }
    if(a.timestamp > b.timestamp){
      return -1
    }
    if(a.timestamp < b.timestamp){
      return 1
    }
}))

但是我似乎无法正常工作.我也想避免使用Lodash.有什么建议吗?

But I can't seem to get it working. I'd like to avoid using Lodash as well. Any suggestions?

推荐答案

在属性user上检查localeCompare的结果，如果它是-1或1，则返回该结果.否则(结果为0)，返回timestamp的比较:

Check the result of localeCompare on the property user, if it is either -1 or 1 then return that result. Otherwise (result is 0), return the comparaison of timestamp:

obj.sort((a,b) => {
    var userComparaison = a.user.localeCompare(b.user);
    if(userComparaison) {                                 // userComparaison is either -1 or 1 (both are thruthy values)
        return userComparaison;                           // return userComparaison as the sorting criteria
    } else {                                              // otherwise (userComparaison is 0 which is falsy)
        return b.timestamp - a.timestamp;                 // compare by timestamp
    }
}

使用逻辑||可以更短:

obj.sort((a,b) => {
    return a.user.localeCompare(b.user) || b.timestamp - a.timestamp;
}

如果localeCompare返回真实值(即 -1或1)，则将返回该真实值，而||的其余部分将被忽略.如果返回假值(即 0)，则将返回||的另一个操作数的值(按timestamp排序)

if localeCompare returned a truthy value (i.e. -1 or 1), then that truthy value will be returned and the rest of || will be ignored. If it returned a falsy value (i.e. 0) then the value of the other operand of || will be returned (which is sorting by timestamp)

这篇关于按两个条件对数据进行排序?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！