使用JavaScript排序方法

排序方法可以修改为使用比较函数对数字、字符串甚至对象数组进行排序。

比较函数作为可选参数传递给排序方法。

此比较函数接受两个参数，通常称为a和b。根据这两个参数可以修改排序方法，使其按需工作。

如果compare函数返回的值小于0，那么sort（）方法将a排序到比b低的索引。如果compare函数返回的值等于0，那么sort（）方法将保持元素位置不变。如果compare函数返回的值大于0，那么sort（）方法会以大于b的索引对a进行排序。

使用上述概念应用于对象，其中a将是对象属性。

var对象=[{first_nom:'Lazslo'，last_nom:'Jamf'}，{first_nom:'猪'，last_nom:'Bodine'}，｛first_nom:'海盗'，last_nom:'Prentice'｝];函数比较（a，b）{如果（a.last_nom>b.last_nom）返回1；如果（a.last_nom<b.last_nom）返回-1；返回0；}objs.sort（比较）；console.log（对象）//要获得更好的外观，请使用console.table（objs）

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

在TypeScript中编程时，也可以创建动态排序函数，但在这种情况下，类型变得更加复杂。

function sortByKey<O>(key: keyof O, decending: boolean = false): (a: O, b: O) => number {
    const order = decending ? -1 : 1;
    return (a, b): number => {
        const valA = a[key];
        const valB = b[key];
        if (valA < valB) {
            return -order;
        } else if (valA > valB) {
            return order;
        } else {
            return 0;
        }
    }
}

这可以在TypeScript中使用，如下所示：

const test = [
    {
        id: 0,
    },
    {
        id: 2,
    }
]

test.sort(sortByKey('id')) // OK
test.sort(sortByKey('id1')) // ERROR
test.sort(sortByKey('')) // ERROR

排序（更多）复杂的对象阵列

由于您可能会遇到类似于此阵列的更复杂的数据结构，因此我将扩展解决方案。

TL；博士

是基于@ege-Özcan非常可爱的答案的更可插拔版本。

问题

我遇到了下面的问题，无法更改它。我也不想暂时压平对象。我也不想使用下划线/lodash，主要是出于性能原因和自己实现它的乐趣。

var People = [
   {Name: {name: "Name", surname: "Surname"}, Middlename: "JJ"},
   {Name: {name: "AAA", surname: "ZZZ"}, Middlename:"Abrams"},
   {Name: {name: "Name", surname: "AAA"}, Middlename: "Wars"}
];

Goal

目标是主要按People.Name.Name排序，其次按People.Name.surname排序

障碍

现在，在基本解决方案中，使用括号表示法来计算要动态排序的财产。不过，在这里，我们还必须动态地构造括号表示法，因为您可能会期望像People['Name.Name']这样的符号会起作用，但这不起作用。

另一方面，简单地做人物['Name']['Name']是静态的，只允许你进入第n层。

解决方案

这里的主要添加是遍历对象树并确定最后一个叶以及任何中间叶的值。

var People = [
   {Name: {name: "Name", surname: "Surname"}, Middlename: "JJ"},
   {Name: {name: "AAA", surname: "ZZZ"}, Middlename:"Abrams"},
   {Name: {name: "Name", surname: "AAA"}, Middlename: "Wars"}
];

People.sort(dynamicMultiSort(['Name','name'], ['Name', '-surname']));
// Results in...
// [ { Name: { name: 'AAA', surname: 'ZZZ' }, Middlename: 'Abrams' },
//   { Name: { name: 'Name', surname: 'Surname' }, Middlename: 'JJ' },
//   { Name: { name: 'Name', surname: 'AAA' }, Middlename: 'Wars' } ]

// same logic as above, but strong deviation for dynamic properties 
function dynamicSort(properties) {
  var sortOrder = 1;
  // determine sort order by checking sign of last element of array
  if(properties[properties.length - 1][0] === "-") {
    sortOrder = -1;
    // Chop off sign
    properties[properties.length - 1] = properties[properties.length - 1].substr(1);
  }
  return function (a,b) {
    propertyOfA = recurseObjProp(a, properties)
    propertyOfB = recurseObjProp(b, properties)
    var result = (propertyOfA < propertyOfB) ? -1 : (propertyOfA > propertyOfB) ? 1 : 0;
    return result * sortOrder;
  };
}

/**
 * Takes an object and recurses down the tree to a target leaf and returns it value
 * @param  {Object} root - Object to be traversed.
 * @param  {Array} leafs - Array of downwards traversal. To access the value: {parent:{ child: 'value'}} -> ['parent','child']
 * @param  {Number} index - Must not be set, since it is implicit.
 * @return {String|Number}       The property, which is to be compared by sort.
 */
function recurseObjProp(root, leafs, index) {
  index ? index : index = 0
  var upper = root
  // walk down one level
  lower = upper[leafs[index]]
  // Check if last leaf has been hit by having gone one step too far.
  // If so, return result from last step.
  if (!lower) {
    return upper
  }
  // Else: recurse!
  index++
  // HINT: Bug was here, for not explicitly returning function
  // https://stackoverflow.com/a/17528613/3580261
  return recurseObjProp(lower, leafs, index)
}

/**
 * Multi-sort your array by a set of properties
 * @param {...Array} Arrays to access values in the form of: {parent:{ child: 'value'}} -> ['parent','child']
 * @return {Number} Number - number for sort algorithm
 */
function dynamicMultiSort() {
  var args = Array.prototype.slice.call(arguments); // slight deviation to base

  return function (a, b) {
    var i = 0, result = 0, numberOfProperties = args.length;
    // REVIEW: slightly verbose; maybe no way around because of `.sort`-'s nature
    // Consider: `.forEach()`
    while(result === 0 && i < numberOfProperties) {
      result = dynamicSort(args[i])(a, b);
      i++;
    }
    return result;
  }
}

实例

JSBin的工作示例

您也可以使用自定义toString（）方法（由默认比较函数调用）创建对象类型，而不是使用自定义比较函数：

function Person(firstName, lastName) {
    this.firtName = firstName;
    this.lastName = lastName;
}

Person.prototype.toString = function() {
    return this.lastName + ', ' + this.firstName;
}

var persons = [ new Person('Lazslo', 'Jamf'), ...]
persons.sort();

如果你有重复的姓氏，你可以按名字排序-

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