从这个最初的问题,我将如何在多个字段应用排序?

使用这种稍作调整的结构,我将如何排序城市(上升)和价格(下降)?

var homes = [
    {"h_id":"3",
     "city":"Dallas",
     "state":"TX",
     "zip":"75201",
     "price":"162500"},
    {"h_id":"4",
     "city":"Bevery Hills",
     "state":"CA",
     "zip":"90210",
     "price":"319250"},
    {"h_id":"6",
     "city":"Dallas",
     "state":"TX",
     "zip":"75000",
     "price":"556699"},
    {"h_id":"5",
     "city":"New York",
     "state":"NY",
     "zip":"00010",
     "price":"962500"}
    ];

我喜欢的事实是,给出的答案提供了一个一般的方法。在我计划使用这段代码的地方,我将不得不对日期以及其他东西进行排序。“启动”对象的能力似乎很方便,如果不是有点麻烦的话。

我试图把这个答案构建成一个很好的通用示例,但我运气不太好。


当前回答

哇,这里有一些复杂的解。如此复杂,我决定想出一些更简单但也相当强大的东西。在这里;

function sortByPriority(data, priorities) {
  if (priorities.length == 0) {
    return data;
  }

  const nextPriority = priorities[0];
  const remainingPriorities = priorities.slice(1);

  const matched = data.filter(item => item.hasOwnProperty(nextPriority));
  const remainingData = data.filter(item => !item.hasOwnProperty(nextPriority));

  return sortByPriority(matched, remainingPriorities)
    .sort((a, b) => (a[nextPriority] > b[nextPriority]) ? 1 : -1)
    .concat(sortByPriority(remainingData, remainingPriorities));
}

这里有一个如何使用它的例子。

const data = [
  { id: 1,                         mediumPriority: 'bbb', lowestPriority: 'ggg' },
  { id: 2, highestPriority: 'bbb', mediumPriority: 'ccc', lowestPriority: 'ggg' },
  { id: 3,                         mediumPriority: 'aaa', lowestPriority: 'ggg' },
];

const priorities = [
  'highestPriority',
  'mediumPriority',
  'lowestPriority'
];


const sorted = sortByPriority(data, priorities);

这将首先根据属性的优先级排序,然后根据属性的值进行排序。

其他回答

一种多维排序方法,基于这个答案:

更新:这是一个“优化”版本。它做了更多的预处理,并预先为每个排序选项创建了一个比较函数。它可能需要更多的内存(因为它为每个排序选项存储了一个函数,但它应该更好一点,因为它不必在比较期间确定正确的设置。不过我没有做过任何侧写。

var sort_by;

(function() {
    // utility functions
    var default_cmp = function(a, b) {
            if (a == b) return 0;
            return a < b ? -1 : 1;
        },
        getCmpFunc = function(primer, reverse) {
            var dfc = default_cmp, // closer in scope
                cmp = default_cmp;
            if (primer) {
                cmp = function(a, b) {
                    return dfc(primer(a), primer(b));
                };
            }
            if (reverse) {
                return function(a, b) {
                    return -1 * cmp(a, b);
                };
            }
            return cmp;
        };

    // actual implementation
    sort_by = function() {
        var fields = [],
            n_fields = arguments.length,
            field, name, reverse, cmp;

        // preprocess sorting options
        for (var i = 0; i < n_fields; i++) {
            field = arguments[i];
            if (typeof field === 'string') {
                name = field;
                cmp = default_cmp;
            }
            else {
                name = field.name;
                cmp = getCmpFunc(field.primer, field.reverse);
            }
            fields.push({
                name: name,
                cmp: cmp
            });
        }

        // final comparison function
        return function(A, B) {
            var a, b, name, result;
            for (var i = 0; i < n_fields; i++) {
                result = 0;
                field = fields[i];
                name = field.name;

                result = field.cmp(A[name], B[name]);
                if (result !== 0) break;
            }
            return result;
        }
    }
}());

使用示例:

homes.sort(sort_by('city', {name:'price', primer: parseInt, reverse: true}));

DEMO


最初的功能:

var sort_by = function() {
   var fields = [].slice.call(arguments),
       n_fields = fields.length;

   return function(A,B) {
       var a, b, field, key, primer, reverse, result, i;

       for(i = 0; i < n_fields; i++) {
           result = 0;
           field = fields[i];

           key = typeof field === 'string' ? field : field.name;

           a = A[key];
           b = B[key];

           if (typeof field.primer  !== 'undefined'){
               a = field.primer(a);
               b = field.primer(b);
           }

           reverse = (field.reverse) ? -1 : 1;

           if (a<b) result = reverse * -1;
           if (a>b) result = reverse * 1;
           if(result !== 0) break;
       }
       return result;
   }
};

DEMO

对两个日期字段和一个数字字段的排序示例:

var generic_date =  new Date(2070, 1, 1);
checkDate = function(date) {
  return Date.parse(date) ? new Date(date): generic_date;
}

function sortData() {  
  data.sort(function(a,b){
    var deltaEnd = checkDate(b.end) - checkDate(a.end);
    if(deltaEnd) return deltaEnd;

    var deltaRank = a.rank - b.rank;
    if (deltaRank) return deltaRank;

    var deltaStart = checkDate(b.start) - checkDate(a.start);
    if(deltaStart) return deltaStart;

    return 0;
  });
}

http://jsfiddle.net/hcWgf/57/

我一直在寻找类似的东西,最后得到了这个:

首先,我们有一个或多个排序函数,总是返回0、1或-1:

const sortByTitle = (a, b): number => 
  a.title === b.title ? 0 : a.title > b.title ? 1 : -1;

您可以为想要排序的其他属性创建更多函数。

然后我有一个函数将这些排序函数合并为一个:

const createSorter = (...sorters) => (a, b) =>
  sorters.reduce(
    (d, fn) => (d === 0 ? fn(a, b) : d),
    0
  );

这可以用来以一种可读的方式组合上述排序函数:

const sorter = createSorter(sortByTitle, sortByYear)

items.sort(sorter)

当一个排序函数返回0时,将调用下一个排序函数进行进一步排序。

通过添加两个辅助函数,可以简单地解决这类问题。sortByKey接受一个数组和一个函数,该函数应返回一个项目列表,用于与每个数组条目进行比较。

这利用了javascript对简单值的数组进行智能比较的事实,即[2]<[2,0]<[2,1]<[10,0]。

// Two helpers: function cmp(a, b) { if (a > b) { return 1 } else if (a < b) { return -1 } else { return 0 } } function sortByKey(arr, key) { arr.sort((a, b) => cmp(key(a), key(b))) } // A demonstration: let arr = [{a:1, b:2}, {b:3, a:0}, {a:1, b:1}, {a:2, b:2}, {a:2, b:1}, {a:1, b:10}] sortByKey(arr, item => [item.a, item.b]) console.log(JSON.stringify(arr)) // '[{"b":3,"a":0},{"a":1,"b":1},{"a":1,"b":10},{"a":1,"b":2},{"a":2,"b":1},{"a":2,"b":2}]' sortByKey(arr, item => [item.b, item.a]) console.log(JSON.stringify(arr)) // '[{"a":1,"b":1},{"a":2,"b":1},{"a":1,"b":10},{"a":1,"b":2},{"a":2,"b":2},{"b":3,"a":0}]'

我从Python的列表中偷取了这个想法。排序功能。

这里有一个简单的泛型函数方法。使用数组指定排序顺序。前置减号以指定降序。

var homes = [
    {"h_id":"3", "city":"Dallas", "state":"TX","zip":"75201","price":"162500"},
    {"h_id":"4","city":"Bevery Hills", "state":"CA", "zip":"90210", "price":"319250"},
    {"h_id":"6", "city":"Dallas", "state":"TX", "zip":"75000", "price":"556699"},
    {"h_id":"5", "city":"New York", "state":"NY", "zip":"00010", "price":"962500"}
    ];

homes.sort(fieldSorter(['city', '-price']));
// homes.sort(fieldSorter(['zip', '-state', 'price'])); // alternative

function fieldSorter(fields) {
    return function (a, b) {
        return fields
            .map(function (o) {
                var dir = 1;
                if (o[0] === '-') {
                   dir = -1;
                   o=o.substring(1);
                }
                if (a[o] > b[o]) return dir;
                if (a[o] < b[o]) return -(dir);
                return 0;
            })
            .reduce(function firstNonZeroValue (p,n) {
                return p ? p : n;
            }, 0);
    };
}

编辑:在ES6中它甚至更短!

"use strict"; const fieldSorter = (fields) => (a, b) => fields.map(o => { let dir = 1; if (o[0] === '-') { dir = -1; o=o.substring(1); } return a[o] > b[o] ? dir : a[o] < b[o] ? -(dir) : 0; }).reduce((p, n) => p ? p : n, 0); const homes = [{"h_id":"3", "city":"Dallas", "state":"TX","zip":"75201","price":162500}, {"h_id":"4","city":"Bevery Hills", "state":"CA", "zip":"90210", "price":319250},{"h_id":"6", "city":"Dallas", "state":"TX", "zip":"75000", "price":556699},{"h_id":"5", "city":"New York", "state":"NY", "zip":"00010", "price":962500}]; const sortedHomes = homes.sort(fieldSorter(['state', '-price'])); document.write('<pre>' + JSON.stringify(sortedHomes, null, '\t') + '</pre>')