如何将数组中的连续整数减少为连字符范围表达式?

How to reduce consecutive integers in an array to hyphenated range expressions?(如何将数组中的连续整数减少为连字符范围表达式?)

问题描述

在 JavaScript 中，如何将数组中的数字序列转换为数字范围?换句话说，我想将连续出现的整数(无间隙)表示为连字符范围.

In JavaScript, how can I convert a sequence of numbers in an array to a range of numbers? In other words, I want to express consecutive occurring integers (no gaps) as hyphenated ranges.

[2,3,4,5,10,18,19,20] 将变为 [2-5,10,18-20]

[1,6,7,9,10,12] 会变成 [1,6-7,9-10,12]

[3,5,99] 将保持 [3,5,99]

[5,6,7,8,9,10,11] 将变为 [5-11]

推荐答案

这是我自己做的一个算法前段时间，最初是为 C# 编写的，现在我将其移植到 JavaScript:

Here is an algorithm that I made some time ago, originally written for C#, now I ported it to JavaScript:

function getRanges(array) {
  var ranges = [], rstart, rend;
  for (var i = 0; i < array.length; i++) {
    rstart = array[i];
    rend = rstart;
    while (array[i + 1] - array[i] == 1) {
      rend = array[i + 1]; // increment the index if the numbers sequential
      i++;
    }
    ranges.push(rstart == rend ? rstart+'' : rstart + '-' + rend);
  }
  return ranges;
}

getRanges([2,3,4,5,10,18,19,20]);
// returns ["2-5", "10", "18-20"]
getRanges([1,2,3,5,7,9,10,11,12,14 ]);
// returns ["1-3", "5", "7", "9-12", "14"]
getRanges([1,2,3,4,5,6,7,8,9,10])
// returns ["1-10"]

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