Question

我正在玩js脚本。如何按月对列表项进行排序。最好的方法是什么？

var dataCollection = [
        { values: { Month: { displayValue: "August" }, Sum: "10" } },
        { values: { Month: { displayValue: "February" }, Sum: "25" } },
        { values: { Month: { displayValue: "July" }, Sum: "35" } }
    ];

我希望得到

dataCollection = [
            { values: { Month: { displayValue: "February" }, Sum: "25" } },
            { values: { Month: { displayValue: "July" }, Sum: "35" } },
            { values: { Month: { displayValue: "August" }, Sum: "10" } }
        ];

Answer 1

您可以通过按正确的顺序列出所有月份的列表，并根据它们对数组进行排序来实现：

var dataCollection = [
  { values: { Month: { displayValue: "August" }, Sum: "10" } },
  { values: { Month: { displayValue: "February" }, Sum: "25" } },
  { values: { Month: { displayValue: "July" }, Sum: "35" } }
];

sortByMonth(dataCollection);

console.log(dataCollection);

function sortByMonth(arr) {
  var months = ["January", "February", "March", "April", "May", "June",
  	        "July", "August", "September", "October", "November", "December"];
  arr.sort(function(a, b){
      return months.indexOf(a.values.Month.displayValue)
           - months.indexOf(b.values.Month.displayValue);
  });
}

Answer 2

在上面@blex的回答（被接受的问题）上功不可没，我想扩展一下以确保排序方法...得到了增强。

// 1. Expect an array of Months, long or short format:
//      ["Jan", "Mar", "Feb"] or ["January", "march", "FEBRUARY"] 
// 2. Support optional reverse sorting.
// 3. Ensure SAFE sorting (does not modify the original array).
function sortByMonthName(monthNames, isReverse = false) {
  const referenceMonthNames = ["jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"];
  const directionFactor = isReverse ? -1 : 1;
  const comparator = (a, b) => {
    if (!a && !b) return 0;
    if (!a && b) return -1 * directionFactor;
    if (a && !b) return 1 * directionFactor;

    const comparableA = a.toLowerCase().substring(0, 3);
    const comparableB = b.toLowerCase().substring(0, 3);
    const comparisonResult = referenceMonthNames.indexOf(comparableA) - referenceMonthNames.indexOf(comparableB);
    return comparisonResult * directionFactor;
  };
  const safeCopyMonthNames = [...monthNames];
  safeCopyMonthNames.sort(comparator);
  return safeCopyMonthNames;
}

// Examples:
const dataset = ["Mar", "January", "DECEMBER", "february"];
const test1 = sortByMonthName(dataset);
const test2 = sortByMonthName(dataset, true);

JavaScript按几个月排序项目列表

2 个答案: