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

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');

其他回答

简单答案:

objs.sort((a,b)=>a.last_nom.localeCompare(b.last_nom))

细节:

今天非常简单,您可以将字符串与localeCompare进行比较。正如Mozilla Doc所说:

localeCompare()方法返回一个数字,指示引用字符串在排序顺序上位于给定字符串之前、之后或与给定字符串相同。

    //example1:
    console.log("aaa".localeCompare("aab")); //-1
    console.log("aaa".localeCompare("aaa")); //0
    console.log("aab".localeCompare("aaa")); //1

    //example2:
    const a = 'réservé'; // with accents, lowercase
    const b = 'RESERVE'; // no accents, uppercase

    console.log(a.localeCompare(b));
    // expected output: 1
    console.log(a.localeCompare(b, 'en', { sensitivity: 'base' }));
    // expected output: 0

有关详细信息,请参阅Mozilla doclocaleCompare:

编写短代码:

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

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},
]

它对我有用。在这里,它将一直保持未定义状态。

函数排序(项、属性、方向){函数比较(a,b){if(!a[property]&&!b[property]){返回0;}否则如果(a[property]&&!b[property]){返回-1;}否则如果(!a[property]&&b[property]){返回1;}其他{const value1=a[property].toString().toUpperCase();//忽略大小写const value2=b[property].toString().toUpperCase();//忽略大小写如果(值1<值2){返回方向==0-1 : 1;}否则如果(值1>值2){返回方向==0?1 : -1;}其他{返回0;}}}返回项目。排序(比较);} 变量项=[{名称:'Edward',值:21},{name:“Sharpe”,值:37},{name:“And”,值:45},{name:“The”,值:-12},{名称:未定义,值:-12},{name:“Magnetic”,值:13},{name:“Zeros”,值:37}];console.log('场景顺序:-');console.log(排序(项,'name',0));console.log('下订单:-');console.log(排序(项,'name',1));

let propName = 'last_nom';

let sorted_obj = objs.sort((a,b) => {
    if(a[propName] > b[propName]) {
        return 1;
    }
    if (a[propName] < b[propName]) {
        return -1;
    }
    return 0;
}

//This works because the js built-in sort function allows us to define our
//own way of sorting, this funny looking function is simply telling `sort` how to
//determine what is larger. 
//We can use `if(a[propName] > b[propName])` because string comparison is already built into JS
//if you try console.log('a' > 'z' ? 'a' : 'z')
//the output will be 'z' as 'a' is not greater than 'z'
//The return values 0,-1,1 are how we tell JS what to sort on. We're sorting on the last_nom property of the object. 
//When sorting a list it comes down to comparing two items and how to determine which one of them is "larger". 
//We need a way to tell JS how to determine which one is larger. 
//The sort defining function will use the case that returns a 1 to mean that a > b
//and the case that returns -1 to mean that a < b