我需要帮助对字符串数组中的特定数字进行排序以下降答案

【问题标题】：I need help sorting specific numbers inside an array of strings to descend我需要帮助对字符串数组中的特定数字进行排序以下降
【发布时间】：2019-07-03 08:33:42
【问题描述】：

我有一个字符串数组，我需要根据每个字符串中的前 4 个数字对这些字符串进行排序。但是我如何针对这些数字进行排序呢？代码运行良好，我只需要对其进行排序。

我试过 .substring 但我认为它不是正确的方法。

var volunteers = [ '9.05', '16.29', '26.67', '0.00', '2.25' ]

getResults: function(volunteers) {
  this.results = [];
  for (var i = 0; i < volunteers.length; i++) {
    var dayNames = this.data[i][3] || " ";
    var result = (volunteers[i] + " additional volunteers are needed on day " + i +" " +dayNames);
    this.results.push(result);        
  }


console.log(this.results)
  return this.results;

}
//Expected
[ '26.67 additional volunteers are needed on day 2 Tuesday',
'16.29 additional volunteers are needed on day 1 Monday',
'9.05 additional volunteers are needed on day 0 Sunday',
'2.25 additional volunteers are needed on day 4 ',
'0.00 additional volunteers are needed on day 3 Wednesday' ]

//Actual
 [ '9.05 additional volunteers are needed on day 0 Sunday',
 '16.29 additional volunteers are needed on day 1 Monday',
 '26.67 additional volunteers are needed on day 2 Tuesday',
 '0.00 additional volunteers are needed on day 3 Wednesday',
 '2.25 additional volunteers are needed on day 4  ' ]

【问题讨论】：

请添加未排序的数组和排序后的版本。
对不起，我做了但没有正确格式化代码
为什么你不能把志愿者数组作为数字而不是字符串，让排序更容易。先对数组排序，再造句子
这些数字来自不同的函数，该函数计算它们并将它们存储到字符串数组中
您可以使用原始volunteers 的indexOf 将volunteers 的排序版本映射到日期

标签： javascript arrays string sorting

【解决方案1】：

var volunteers = [ '9.05', '16.29', '26.67', '0.00', '2.25' ];

var days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];

this.results = [];
for (var i = 0; i < volunteers.length; i++) {
  var result = {
    'value':volunteers[i] , 
    'name' : volunteers[i] + " additional volunteers are needed on day " + i +" " +days[i]
  }
  this.results.push(result);
}

this.results.sort(function(a, b) {
  return a.value - b.value;
}).reverse();

var result = this.results.map(a => a.name);

console.log(result);

【讨论】：

【解决方案2】：

先排序：

getResults: function(volunteers) {
  volunteers = volunteers.sort((a, b) => +a - +b);
  // Use sorted `volunteers` 
}

【讨论】：

这只是对数字进行排序，虽然这是我需要的一部分，但这些数字需要将它们各自的日期保持在同一行。

【解决方案3】：

试试这个：

function getNumber(string) {
  const numbers = string.match(/[0-9\.]+/g)[0] || 0
  return Number(numbers);
}
function sort (volunteers) {
  return volunteers.sort((a, b) => getNumber(a) - getNumber(b));
}
sort(volunteers)

【讨论】：

【解决方案4】：

您可以获取索引并使用值降序对它们进行排序，并使用排序后的索引映射字符串。

var volunteers = ['9.05', '16.29', '26.67', '0.00', '2.25'],
    days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
    result = [...volunteers.keys()]
        .sort((a, b) => volunteers[b] - volunteers[a])
        .map(i => `${volunteers[i]} additional volunteers are needed on day ${i} ${days[i]}`);

console.log(result);

【讨论】：

【解决方案5】：

parseFloat 可用于获取数字部分：

var arr = [ '9.05 additional volunteers are needed on day 0 Sunday',
           '16.29 additional volunteers are needed on day 1 Monday',
           '26.67 additional volunteers are needed on day 2 Tuesday',
            '0.00 additional volunteers are needed on day 3 Wednesday',
           '2.25 additional volunteers are needed on day 4' ]

console.log( arr.sort((a, b) => parseFloat(b) - parseFloat(a)) )

【讨论】：