如何根据字符串中的数字对数组进行排序? [英] How to sort array based on the numbers in string?

问题描述

给出此数组= [ "3ab1", "2a0", "1abc2" ]

如何将其排序为[ "1abc2", "3ab1", "2a0" ](最后一个数字的降序)

How do I sort it to [ "1abc2", "3ab1", "2a0" ] (descending order of the last number)

并返回[ 1,3,2 ]. (每学期的第一个数字)

and return [ 1,3,2 ]. (the first numbers of each term)

当最后一个数字和下一个最后一个数字不连续时，返回的值应为0.

When the last number and the next last number is not consecutive, the value returned should be 0.

[ "2x2", "3x0", "2x1" ] ==> [ 2, 2, 3 ]

[ "22x0", "3x9", "2x1" ] ==> [ 3, 0, 0, 0, 0, 0, 0, 0, 2, 22 ]

[ "2x4", "3x0" ] ==> [ 2, 0, 0, 3 ]

[ "axn", "bx(n-2)" ] ==> [ "axn", "0x(n-1)", bx(n-2) ] ==> [ a, 0, b ]

我正在考虑将数组转换为字符串，替换前面的数字和字母，然后对数组进行排序.但是我不知道如何将更换的零件放回原来的编号.这是我对排序后的最终数组返回的尝试.

I was thinking of converting to the array to string, replacing the number and letters in front and then sorting the array. But I do not know how put the part that was replaced back to its original number. This is my attempt on returning the final array once it is sorted.

var ary = [ "1abc2", "3ab1", "2a0" ];

console.log(((ary.toString()).match(/\d+(?!,)/g)).slice(0, -1));

我在根据数字对数组进行排序时看到了这些问题，但它们似乎对我不起作用.

I saw these questions on sorting arrays based on numbers but they do not seem to work for me.

如何正确对整数数组进行排序

排序数组元素(带有数字的字符串)，自然排序

推荐答案

使用sort和reduce获取结果时，可以使用正则表达式获取数字:

You can use regular expression to get the numbers when using sort and reduce to get the result:

var array = [ "22x0", "3x9", "2x1" ];

var reS = /^\d+/,                          // regexp for getting all digits at the start of the string
    reE = /\d+$/;                          // regexp for getting all digits at the end of the string
var result = array.sort(function(a, b) {   // First: sort the array
    a = reE.exec(a);                       // get the last number from the string a
    b = reE.exec(b);                       // get the last number from the string b
    return b - a;                          // sort in a descending order
}).reduce(function(res, str, i) {          // Then: accumulate the result array 
    var gap = reE.exec(array[i - 1]) - reE.exec(str); // calculate the gap between this string str and the last string array[i - 1] (gap = N_of_last_string - N_of_this_string)
    if(gap > 0)                            // if there is a gap
        while(--gap) res.push(0);          // then fill it with 0s
    res.push(+reS.exec(str));              // push this string number
    return res;
}, []);

console.log("Sorted array:", array);       // array is now sorted
console.log("Result:", result);            // result contain the numbers

在最新的ECMAScript版本中，您可以使用以下箭头功能很快完成此操作:

In recent ECMAScript versions you can do it shortly using arrow functions like this:

let array = [ "22x0", "3x9", "2x1" ];

let reS = /^\d+/,                       
    reE = /\d+$/;                      
let result = array.sort((a, b) => reE.exec(b) - reE.exec(a))
                  .reduce((res, str, i) => { 
                      let gap = reE.exec(array[i - 1]) - reE.exec(str);
                      if(gap > 0)
                          while(--gap) res.push(0);
                      res.push(+reS.exec(str));
                      return res;
                  }, []);

console.log("Sorted array:", array); 
console.log("Result:", result);

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