对象数组返回最近日期的最高总价值

Question

我有类似的结构：

var array = [
  {
    "overall": 8,
    "date": "2016-03-15",
    "review": "bla bla",
  },
  {
    "overall": 6,
    "date": "2016-01-19",
    "review": "asfasfsadfsd",
  },
  {
    "overall": 7,
    "date": "2016-01-23",
    "review": "adfsasfdasfas",
  }];

返回最大值：

var highestScore = Math.max.apply(Math,array.map(function(o){return o.overall;}));

如何过滤此数组以获取与最近日期的最高总价值相关的评论？在这种情况下“bla bla”

Answer 1

不需要对数组进行排序，因为您只想获得最高值。所以使用 reduce() 并使用 Date.parse() 比较日期字符串。

var array = [{
  "overall": 5,
  "date": "2016-03-15",
  "review": "sadas sasdadasdas",
}, {
  "overall": 6,
  "date": "2016-01-19",
  "review": "asfasfsadfsd",
}, {
  "overall": 9,
  "date": "2016-03-15",
  "review": "sadas sasdadasdas",
}, {
  "overall": 7,
  "date": "2016-01-23",
  "review": "adfsasfdasfas",
}];

var res = array.reduce(function(a, b) {
  // parse the date
  var d1 = Date.parse(a.date),
    d2 = Date.parse(b.date);
  // if dates are equal compare value of overall and return value , else return based on date
  return d1 == d2 ? (a.overall > b.overall ? a : b) : (d1 > d2 ? a : b);
}).overall; // get overall value from final object

document.write(res);

Answer 2

你可以使用.sort()。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

var array = [{
  "overall": 5,
  "date": "2016-03-15",
  "review": "sadas sasdadasdas",
}, {
  "overall": 6,
  "date": "2016-01-19",
  "review": "asfasfsadfsd",
}, {
  "overall": 7,
  "date": "2016-01-23",
  "review": "adfsasfdasfas",
}];
var sortedArray = array.sort(function(a, b) {
  var aDate = Date.parse(a.date);
  var bDate = Date.parse(b.date);
  if (aDate > bDate) {
    return true;
  } else if(aDate == bDate) {
    return a.overall > b.overall;
  } else {
    return false;
  }
});
//hello
var isItMeYoureLookingFor = sortedArray[0];

基本上，按条件排序，取第一个:)。

Answer 3

使用普通数组迭代：

function newestHighestOverall(arr){
  if(arr.length == 0) return 0;

  var latestDate = new Date(arr[0].date);
  var highestOverall = arr[0].overall;

  for(var i=0;i<arr.length;i++){
    if(latestDate < new Date(arr[i].date)){
        highestOverall = arr[i].overall;
        latestDate = new Date(arr[i].date);
    }else if(latestDate == new Date(arr[i].date)){
        highestOverall = Math.max(highestOverall, arr[i].overall);
    }
  }
  return highestOverall
}

console.log(newestHighestOverall(array))

Answer 4

您可以使用sort 并首先通过date 进行比较，然后通过overall 进行比较，并返回review。

var array = [{
  "overall": 8,
  "date": "2016-03-15",
  "review": "bla bla",
},{
  "overall": 20,
  "date": "2016-03-15",
  "review": "Random bla bla",
}, {
  "overall": 6,
  "date": "2016-01-19",
  "review": "asfasfsadfsd",
}, {
  "overall": 7,
  "date": "2016-01-23",
  "review": "adfsasfdasfas",
}];

result = array.sort((a, b) => {
  return Date.parse(b.date) - Date.parse(a.date) || b.overall - a.overall;
})[0].review;
console.log(result)