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

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

其他回答

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");

将Ege的动态解决方案与Vinay的想法相结合,您可以得到一个很好的鲁棒解决方案:

Array.prototype.sortBy=函数(){函数_sortByAttr(属性){var sortOrder=1;如果(属性[0]==“-”){sortOrder=-1;attr=attr.substr(1);}返回函数(a,b){var结果=(a[attr]<b[attr])-1:(a[attr]>b[attr])?1 : 0;返回结果*sortOrder;}}函数_getSortFunc(){if(arguments.length==0){throw“Array.sortBy()不允许零长度参数”;}var args=参数;返回函数(a,b){for(var result=0,i=0;result==0&&i<args.length;i++){result=_sortByAttr(args[i])(a,b);}返回结果;}}返回this.sort(_getSortFunc.apply(null,arguments));}用法://用于打印对象的实用程序Array.prototype.print=函数(标题){console.log(“************************************************************”);console.log(“***”+标题);console.log(“************************************************************”);对于(var i=0;i<this.length;i++){console.log(“名称:”+此[i].FirstName,此[i].LastName,“年龄:”+该[i].Age);}}//设置示例数据变量arrObj=[{名字:“Zach”,姓氏:“Emergency”,年龄:35岁},{名字:“Nancy”,姓氏:“护士”,年龄:27岁},{名字:“Ethel”,姓氏:“Emergency”,年龄:42岁},{名字:“Nina”,姓氏:“护士”,年龄:48岁},{名字:“Anthony”,姓氏:“Emergency”,年龄:44岁},{名字:“Nina”,姓氏:“护士”,年龄:32岁},{名字:“Ed”,姓氏:“Emergency”,年龄:28岁},{名字:“Peter”,姓氏:“医生”,年龄:58岁},{名字:“Al”,姓氏:“Emergency”,年龄:51岁},{名字:“Ruth”,姓氏:“注册”,年龄:62岁},{名字:“Ed”,姓氏:“Emergency”,年龄:38岁},{名字:“Tammy”,姓氏:“Triage”,年龄:29岁},{名字:“Alan”,姓氏:“Emergency”,年龄:60岁},{名字:“Nina”,姓氏:“护士”,年龄:54岁}];//单元测试arrObj.sortBy(“姓氏”).print(“姓氏升序”);arrObj.sortBy(“-姓氏”).print(“姓氏降序”);arrObj.sortBy(“姓氏”、“名字”、“年龄”).print(“姓氏升序、名字升序、年龄降序”);arrObj.sortBy(“-FirstName”,“Age”).print(“FirstName降序,Age升序”);arrObj.sortBy(“-Age”).print(“Age Descending”);

您可以使用可重用的排序函数。

Array.prototype.order = function (prop, methods = {}) {
    if (prop?.constructor == Object) {
        methods = prop;
        prop = null;
    }
    const [orderType_a, orderType_b] = methods.reverse ? [1, -1] : [-1, 1];

    const $ = x => prop
        ? methods.insensitive
            ? String(x[prop]).toLowerCase()
            : x[prop]
        : methods.insensitive
            ? String(x).toLowerCase()
            : x;

    const fn = (a, b) => $(a) < $(b) ? orderType_a : $(b) < $(a) ? orderType_b : 0;
    return this.sort(fn);
};

它可用于对数组和数组中的对象进行排序。

let items = [{ x: "Z" }, 3, "1", "0", 2, { x: "a" }, { x: 0 }];
items
    .order("x", { insensitive: 1 })
    // [ { x: 0 }, { x: 'a' }, 3, '1', '0', 2, { x: 'Z' } ]
    .order({ reverse: 1 })
    // [ { x: 0 }, { x: 'a' }, 3, 2, { x: 'Z' }, '1', '0' ]
    .sort(x => typeof x == "string" || typeof x == "number" ? -1 : 0)
    // [ '0', '1', 2, 3, { x: 0 }, { x: 'a' }, { x: 'Z' } ]

1nd(可选)>对数组中包含的对象进行排序。2rd是方法>{reverse:any,不敏感:any}

我将给您一个实现选择排序算法的解决方案。它简单有效。

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


function selection_Sort(num) {
  //console.log(num);
  var temp, index;
  for (var i = 0; i <= num.length - 1; i++) {
    index = i;

    for (var j = i + 1; j <= num.length - 1; j++) {
      // You can use first_nom/last_nom, any way you choose to sort

      if (num[j].last_nom < num[index].last_nom) {
        index = j;
      }
    }

    // Below is the swapping part
    temp = num[i].last_nom;
    num[i].last_nom = num[index].last_nom;
    num[index].last_nom = temp;
  };
  console.log(num);
  return num;
}

selection_Sort(objs);

我遇到了排序对象数组的问题,改变了值的优先级。基本上,我想按年龄,然后按姓氏,或者仅仅按姓氏,名字来对一系列人进行排序。

我认为与其他答案相比,这是最简单的解决方案。

它用于调用sortPeoples(['array','of','properties'],reverse=false)。

///////////////////////人群示例阵列///////////////////////var人民=[{姓名:“Zach”,姓:“Emergency”,年龄:1},{姓名:“南希”,姓:“护士”,年龄:1岁},{姓名:“Ethel”,姓:“Emergency”,年龄:1},{姓名:“尼娜”,姓:“护士”,年龄:42岁},{姓名:“Anthony”,姓:“Emergency”,年龄:42岁},{姓名:“尼娜”,姓:“护士”,年龄:32岁},{姓名:“Ed”,姓:“Emergency”,年龄:28岁},{姓名:“彼得”,姓:“医生”,年龄:58岁},{姓名:“Al”,姓:“Emergency”,年龄:58岁},{姓名:“Ruth”,姓:“Registration”,年龄:62岁},{姓名:“Ed”,姓:“Emergency”,年龄:38岁},{姓名:“Tammy”,姓:“Triage”,年龄:29岁},{姓名:“Alan”,姓:“Emergency”,年龄:60岁},{姓名:“尼娜”,姓:“护士”,年龄:58岁}];////////////////////////排序功能/////////////////////函数sortPeoples(propertyArr,reverse){函数比较(a,b){变量i=0;while(propertyArr[i]){如果(a[propertyArr[i]]<b[propertyAr[i]])返回-1;如果(a[propertyArr[i]]>b[propertyAr[i]])返回1;i++;}返回0;}人民。排序(比较);if(反向){peoples.reverse();}};////////////////排序方法结束///////////////函数printPeoples(){$(“#输出”).html(“”);people.forEach(功能(人){$('#output').append(person.surname+“”+person.name+““”+person.age+“<br>”);})}<head><script src=“https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js“></script></head><html><body><button onclick=“sortPeoples(['surname']);printPeoples()”>仅按姓氏ASC排序会导致同名案例的混乱</button><br><button onclick=“sortPeoples(['surname','name],true);printPeoples()”>按姓氏排序,然后按名称DESC</button><br><button onclick=“sortPeoples(['age']);printPeoples()”>按age ASC排序。与第一种情况相同的问题</button><br><button onclick=“sortPeoples(['age','姓']);printPeoples()”>按age和姓氏ASC排序。添加第二个字段修复了它。</button><br><div id=“output”></div></body></html>