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

根据您的示例,您需要按两个字段(姓、名)排序,而不是一个。您可以使用Alasql库在一行中进行排序:

var res = alasql('SELECT * FROM ? ORDER BY last_nom, first_nom',[objs]);

在JSFiddle中尝试此示例。

其他回答

下划线.js

使用Undercore.js]。它很小,非常棒。。。

sortBy_.sortBy(列表,迭代器,[context])返回列表,按运行每个值的结果升序排列通过迭代器。迭代器也可以是属性的字符串名称按(例如长度)排序。

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

var sortedObjs = _.sortBy(objs, 'first_nom');

编写短代码:

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

您还可以创建一个动态排序函数,根据传递的值对对象进行排序:

function dynamicSort(property) {
    var sortOrder = 1;
    if(property[0] === "-") {
        sortOrder = -1;
        property = property.substr(1);
    }
    return function (a,b) {
        /* next line works with strings and numbers, 
         * and you may want to customize it to your needs
         */
        var result = (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0;
        return result * sortOrder;
    }
}

所以你可以有一个这样的对象数组:

var People = [
    {Name: "Name", Surname: "Surname"},
    {Name:"AAA", Surname:"ZZZ"},
    {Name: "Name", Surname: "AAA"}
];

…当你这样做时,它会起作用:

People.sort(dynamicSort("Name"));
People.sort(dynamicSort("Surname"));
People.sort(dynamicSort("-Surname"));

事实上,这已经回答了问题。下面的部分是因为许多人联系我,抱怨它不适用于多个参数。

多个参数

您可以使用下面的函数生成具有多个排序参数的排序函数。

function dynamicSortMultiple() {
    /*
     * save the arguments object as it will be overwritten
     * note that arguments object is an array-like object
     * consisting of the names of the properties to sort by
     */
    var props = arguments;
    return function (obj1, obj2) {
        var i = 0, result = 0, numberOfProperties = props.length;
        /* try getting a different result from 0 (equal)
         * as long as we have extra properties to compare
         */
        while(result === 0 && i < numberOfProperties) {
            result = dynamicSort(props[i])(obj1, obj2);
            i++;
        }
        return result;
    }
}

这将使您能够执行以下操作:

People.sort(dynamicSortMultiple("Name", "-Surname"));

子类化数组

对于我们中能够使用ES6的幸运者,ES6允许扩展本机对象:

class MyArray extends Array {
    sortBy(...args) {
        return this.sort(dynamicSortMultiple(...args));
    }
}

这将实现:

MyArray.from(People).sortBy("Name", "-Surname");

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"}
*/

尝试以下方式:

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

const compareBylastNom = (a, b) => {
    // Converting to uppercase to have case-insensitive comparison
    const name1 = a.last_nom.toUpperCase();
    const name2 = b.last_nom.toUpperCase();

    let comparison = 0;

    if (name1 > name2) {
        comparison = 1;
    } else if (name1 < name2) {
        comparison = -1;
    }
    return comparison;
}

console.log(objs.sort(compareBylastNom));