JavaScript数组sort方法详解：从默认排序到自定义排序

var arr=[1,3,5,9,4];
console.log(arr.sort());
// 输出: [1, 3, 4, 5, 9]

var arr=[101,1,3,5,9,4,11];
console.log(arr.sort());
// 输出: [1, 101, 11, 3, 4, 5, 9]

...
// 转码方法
function getUnicode (charCode) {
  return charCode.charCodeAt(0).toString(16);
}
// 打印转码
arr.forEach((n)=>{
 console.log(getUnicode(String(n)))
});

// 输出: 31 31 31 33 34 35 39

function compare(value1,value2){
 if (value1 < value2){
  return -1;
 } else if (value1 > value2){
  return 1;
 } else{
  return 0;
 }
}

var arr=[101,1,3,5,9,4,11];
console.log(arr.sort(compare));
// 输出: [1, 3, 4, 5, 9, 11, 101];

function compareFunc(prop){
 return function (obj1,obj2){
  var value1=obj1[prop];
  var value2=obj2[prop];
  if (value1 < value2){
    return -1;
  } else if (value1 > value2){
    return 1;
  } else{
    return 0;
  }
 }
}

var users=[
  {name:'tom',age:18},
  {name:'lucy',age:24},
  {name:'jhon',age:17},
];
console.log(users.sort(compareFunc('age')));
// 输出结果
[{name: "jhon", age: 17},
{name: "tom", age: 18},
{name: "lucy", age: 24}]

// 1.模拟后端返回的XML字符串
var str=`
<root>
 <user>
  <name>tom</name>
  <age>18</age>
 </user>
 <user>
  <name>lucy</name>
  <age>24</age>
 </user>
 <user>
  <name>jhon</name>
  <age>17</age>
 </user>
<root>
`  
// 2.定义比较函数
function compareFunction(prop){
 return function (a, b) {
   var value1= a.getElementsByTagName(prop)[0].textContent;
   var value2= b.getElementsByTagName(prop)[0].textContent;
   if (value1 < value2){
    return -1;
   } else if (value1 > value2){
    return 1;
   } else{
    return 0;
  }
 }
}
// 3.xml字符串转换成xml对象
var domParser = new DOMParser();
var xmlDoc = domParser.parseFromString(str, 'text/xml');
var userElements=xmlDoc.getElementsByTagName('user'));
// 4.userElements类数组对象转换成数组再排序
var userElements=Array.prototype.slice.call(xmlDoc.getElementsByTagName('user'));
var _userElements=userElements.sort(compareFunction('age'));
// 5.打印排序后的结果
_userElements.forEach((user)=>{
 console.log(user.innerHTML);
});