我有一个JavaScript对象数组:

var objs = [ 
    { first_nom: 'Lazslo', last_nom: 'Jamf'     },
    { first_nom: 'Pig',    last_nom: 'Bodine'   },
    { first_nom: 'Pirate', last_nom: 'Prentice' }
];

如何在JavaScript中按last_nom的值对它们进行排序?

我知道排序(a,b),但这似乎只适用于字符串和数字。是否需要向对象添加toString()方法?


当前回答

EgeÖzcan代码的其他描述参数:

function dynamicSort(property, desc) {
    if (desc) {
        return function (a, b) {
            return (a[property] > b[property]) ? -1 : (a[property] < b[property]) ? 1 : 0;
        }
    }
    return function (a, b) {
        return (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0;
    }
}

其他回答

这里有一个函数,您可以使用它按多个对象对列表进行排序,如果第一个对象相等,则第二个顺序将用作回退。如果可能的话,空值也应忽略到回退顺序。

function sortObjects(list, orderBy){
    list.sort(function(a, b){
        let byIndex = 0;
        let order = orderBy[byIndex];
        while(!a[order.by] || !b[order.by] || a[order.by] === b[order.by]){
            byIndex++;
            if(byIndex >= orderBy.length){break;}
            order = orderBy[byIndex];
        }
        if(!a[order.by] || !b[order.by] || a[order.by] === b[order.by]){
            return false;
        }
        if(order.desc){
            return a[order.by] < b[order.by];
        }
        return a[order.by] > b[order.by];
    });
    return list;
}

用法:

var objs = [
    {a: 10, b: 20, c: 30},
    {a: 30, b: 10, c: 20},
    {a: 20, b: 10, c: 30},
];

sortObjectList(objs, [{by: 'a'}]);
[
    {a: 10, b: 20, c: 30},
    {a: 20, b: 10, c: 30},
    {a: 30, b: 10, c: 20},
]

sortObjectList(objs, [{by: 'a', desc: true}]);
[
    {a: 30, b: 10, c: 20},
    {a: 20, b: 10, c: 30},
    {a: 10, b: 20, c: 30},
]

sortObjectList(objs, [{by: 'b', desc: true}, {by: 'c'}]);
[
    {a: 10, b: 20, c: 30},
    {a: 30, b: 10, c: 20},
    {a: 20, b: 10, c: 30},
]

另一个例子:

var objs = [
    {a: 5, b: 5},
    {a: 10, b: 15},
    {a: 15, b: 25},
    {b: 10},
    {b: 20},
    {a: 10, b: 30},
    {a: 10, b: 12},
];

sortObjectList(objs, [{by: 'a'}, {by: 'b'}]);
[
    {a: 5, b: 5},
    {b: 10},
    {a: 10, b: 12},
    {a: 10, b: 15},
    {b: 20},
    {a: 10, b: 30},
    {a: 15, b: 25},
]

使用xPrototype的sortBy:

var o = [
  { Name: 'Lazslo', LastName: 'Jamf'     },
  { Name: 'Pig',    LastName: 'Bodine'   },
  { Name: 'Pirate', LastName: 'Prentice' },
  { Name: 'Pag',    LastName: 'Bodine'   }
];


// Original
o.each(function (a, b) { console.log(a, b); });
/*
 0 Object {Name: "Lazslo", LastName: "Jamf"}
 1 Object {Name: "Pig", LastName: "Bodine"}
 2 Object {Name: "Pirate", LastName: "Prentice"}
 3 Object {Name: "Pag", LastName: "Bodine"}
*/


// Sort By LastName ASC, Name ASC
o.sortBy('LastName', 'Name').each(function(a, b) { console.log(a, b); });
/*
 0 Object {Name: "Pag", LastName: "Bodine"}
 1 Object {Name: "Pig", LastName: "Bodine"}
 2 Object {Name: "Lazslo", LastName: "Jamf"}
 3 Object {Name: "Pirate", LastName: "Prentice"}
*/


// Sort by LastName ASC and Name ASC
o.sortBy('LastName'.asc, 'Name'.asc).each(function(a, b) { console.log(a, b); });
/*
 0 Object {Name: "Pag", LastName: "Bodine"}
 1 Object {Name: "Pig", LastName: "Bodine"}
 2 Object {Name: "Lazslo", LastName: "Jamf"}
 3 Object {Name: "Pirate", LastName: "Prentice"}
*/


// Sort by LastName DESC and Name DESC
o.sortBy('LastName'.desc, 'Name'.desc).each(function(a, b) { console.log(a, b); });
/*
 0 Object {Name: "Pirate", LastName: "Prentice"}
 1 Object {Name: "Lazslo", LastName: "Jamf"}
 2 Object {Name: "Pig", LastName: "Bodine"}
 3 Object {Name: "Pag", LastName: "Bodine"}
*/


// Sort by LastName DESC and Name ASC
o.sortBy('LastName'.desc, 'Name'.asc).each(function(a, b) { console.log(a, b); });
/*
 0 Object {Name: "Pirate", LastName: "Prentice"}
 1 Object {Name: "Lazslo", LastName: "Jamf"}
 2 Object {Name: "Pag", LastName: "Bodine"}
 3 Object {Name: "Pig", LastName: "Bodine"}
*/

编写自己的比较函数非常简单:

function compare( a, b ) {
  if ( a.last_nom < b.last_nom ){
    return -1;
  }
  if ( a.last_nom > b.last_nom ){
    return 1;
  }
  return 0;
}

objs.sort( compare );

或内联(由Marco Demaio转交):

objs.sort((a,b) => (a.last_nom > b.last_nom) ? 1 : ((b.last_nom > a.last_nom) ? -1 : 0))

或简化为数字(由Andre Figueiredo转交):

objs.sort((a,b) => a.last_nom - b.last_nom); // b - a for reverse sort

Lodash(Undercore.js的超集)。

不为每一个简单的逻辑添加一个框架是很好的,但是依赖于经过良好测试的实用程序框架可以加快开发并减少错误数量。

Lodash生成了非常干净的代码,并促进了更具功能性的编程风格。一眼望去,代码的意图就一目了然了。

OP的问题可以简单地解决为:

const sortedObjs = _.sortBy(objs, 'last_nom');

更多信息?例如,我们有以下嵌套对象:

const users = [
  { 'user': {'name':'fred', 'age': 48}},
  { 'user': {'name':'barney', 'age': 36 }},
  { 'user': {'name':'wilma'}},
  { 'user': {'name':'betty', 'age': 32}}
];

我们现在可以使用_.properties速记user.age来指定应该匹配的属性的路径。我们将根据嵌套的年龄属性对用户对象进行排序。是的,它允许嵌套属性匹配!

const sortedObjs = _.sortBy(users, ['user.age']);

想要反转吗?没问题。使用_反向。

const sortedObjs = _.reverse(_.sortBy(users, ['user.age']));

想用链条将两者结合起来吗?

const { chain } = require('lodash');
const sortedObjs = chain(users).sortBy('user.age').reverse().value();

或者你什么时候更喜欢流动而不是链条?

const { flow, reverse, sortBy } = require('lodash/fp');
const sortedObjs = flow([sortBy('user.age'), reverse])(users);

您可以使用最简单的方式:Lodash

(https://lodash.com/docs/4.17.10#orderBy)

此方法类似于_.sortBy,只是它允许指定要排序的迭代项的排序顺序。如果未指定顺序,则所有值都按升序排序。否则,为相应值的降序指定“desc”,为升序指定“asc”。

论据

collection(Array | Object):要迭代的集合。[iteratees=[_.identity]](数组[]|函数[]|对象[]|字符串[]):要排序的iterates。[orders](string[]):迭代的排序顺序。

退换商品

(Array):返回新的排序数组。


var _ = require('lodash');
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"}
    ];
    
_.orderBy(homes, ['city', 'state', 'zip'], ['asc', 'desc', 'asc']);