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

只需遵循排序标准列表

即使要封装36个排序标准,这段代码也将始终保持可读和可理解

Nina在这里提出的解决方案当然非常优雅,但它意味着要知道在布尔逻辑中,值为0对应的值为false,并且布尔测试在JavaScript中可以返回除true / false以外的值(这里是数值),这对于初学者来说总是令人困惑。

还要考虑谁需要维护您的代码。也许会是你:想象一下你自己花了几天的时间在另一个人的代码上,然后有了一个有害的错误……你读了几千行充满技巧的文章,都累坏了

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 fSort = (a,b) => { let Dx = a.city.localeCompare(b.city) // 1st criteria if (Dx===0) Dx = Number(b.price) - Number(a.price) // 2nd // if (Dx===0) Dx = ... // 3rd // if (Dx===0) Dx = ... // 4th.... return Dx } console.log( homes.sort(fSort))

其他回答

这是另一个可能更接近您对语法的想法的例子

function sortObjects(objArray, properties /*, primers*/) {
    var primers = arguments[2] || {}; // primers are optional

    properties = properties.map(function(prop) {
        if( !(prop instanceof Array) ) {
            prop = [prop, 'asc']
        }
        if( prop[1].toLowerCase() == 'desc' ) {
            prop[1] = -1;
        } else {
            prop[1] = 1;
        }
        return prop;
    });

    function valueCmp(x, y) {
        return x > y ? 1 : x < y ? -1 : 0; 
    }

    function arrayCmp(a, b) {
        var arr1 = [], arr2 = [];
        properties.forEach(function(prop) {
            var aValue = a[prop[0]],
                bValue = b[prop[0]];
            if( typeof primers[prop[0]] != 'undefined' ) {
                aValue = primers[prop[0]](aValue);
                bValue = primers[prop[0]](bValue);
            }
            arr1.push( prop[1] * valueCmp(aValue, bValue) );
            arr2.push( prop[1] * valueCmp(bValue, aValue) );
        });
        return arr1 < arr2 ? -1 : 1;
    }

    objArray.sort(function(a, b) {
        return arrayCmp(a, b);
    });
}

// just for fun use this to reverse the city name when sorting
function demoPrimer(str) {
    return str.split('').reverse().join('');
}

// Example
sortObjects(homes, ['city', ['price', 'desc']], {city: demoPrimer});

演示:http://jsfiddle.net/Nq4dk/2/


编辑:只是为了好玩,这里有一个变化,只需要一个类似sql的字符串,所以你可以做sortObjects(房屋,“城市,价格desc”)

function sortObjects(objArray, properties /*, primers*/) {
    var primers = arguments[2] || {};

    properties = properties.split(/\s*,\s*/).map(function(prop) {
        prop = prop.match(/^([^\s]+)(\s*desc)?/i);
        if( prop[2] && prop[2].toLowerCase() === 'desc' ) {
            return [prop[1] , -1];
        } else {
            return [prop[1] , 1];
        }
    });

    function valueCmp(x, y) {
        return x > y ? 1 : x < y ? -1 : 0; 
    }

    function arrayCmp(a, b) {
        var arr1 = [], arr2 = [];
        properties.forEach(function(prop) {
            var aValue = a[prop[0]],
                bValue = b[prop[0]];
            if( typeof primers[prop[0]] != 'undefined' ) {
                aValue = primers[prop[0]](aValue);
                bValue = primers[prop[0]](bValue);
            }
            arr1.push( prop[1] * valueCmp(aValue, bValue) );
            arr2.push( prop[1] * valueCmp(bValue, aValue) );
        });
        return arr1 < arr2 ? -1 : 1;
    }

    objArray.sort(function(a, b) {
        return arrayCmp(a, b);
    });
}

您可以使用lodash或derby函数lodash

它有两个参数字段数组和方向数组('asc','desc')

  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"}
    ];

var sorted =. data._.orderBy(data, ['city', 'price'], ['asc','desc'])

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

下面是一种可扩展的按多个字段排序的方法。

homes.sort(function(left, right) {
    var city_order = left.city.localeCompare(right.city);
    var price_order = parseInt(left.price) - parseInt(right.price);
    return city_order || -price_order;
});

笔记

A function passed to array sort is expected to return negative, zero, positive to indicate less, equal, greater. a.localeCompare(b) is universally supported for strings, and returns -1,0,1 if a<b,a==b,a>b. Subtraction works on numeric fields, because a - b gives -,0,+ if a<b,a==b,a>b. || in the last line gives city priority over price. Negate to reverse order in any field, as in -price_order Add new fields to the or-chain: return city_order || -price_order || date_order; Date compare with subtraction, because date math converts to milliseconds since 1970.var date_order = new Date(left.date) - new Date(right.date); Boolean compare with subtraction, which is guaranteed to turn true and false to 1 and 0 (therefore the subtraction produces -1 or 0 or 1). var goodness_order = Boolean(left.is_good) - Boolean(right.is_good)This is unusual enough that I'd suggest drawing attention with the Boolean constructor, even if they're already boolean.

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/