1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 <script type="text/javascript">
7
8 /**
9 * 由于函数是对象，所以可以直接把函数通过参数传递进来
10 * @param fun 函数对象
11 * @param arg 参数
12 * @returns {*}
13 */
14 function callFun(fun , arg){
15 //第一个参数就是函数对象
16 return fun(arg);
17 }
18
19 function say(str){
20 alert("hello:" + str);
21 }
22
23 function sum(num){
24 return num + 100 ;
25 }
26
27 //调用了say函数
28 callFun(say , "Leon"); //hello:Leon
29 //调用了sum函数
30 alert(callFun(sum,20)); //120
31
32 function fn1(arg){
33
34 /**
35 * 此时返回i的是一个函数对象，
36 */
37 var rel = function(num){
38 console.info("inner:" + num + " arg: " + arg);
39 return arg + num ;
40 }
41 console.info("outter arg: " + arg);
42 return rel;
43 }
44
45 //此时f是一个函数对象,可以完成调用
46 var f = fn1(20); //控制台输出值： outter arg: 20
47 console.info(f); //控制台输出值： function(num)
48 console.info("-------------");
49 alert(f(11)); //控制台输出值：inner:11 arg: 20 运行结果：31
50
51 </script>
52
53 </head>
54 <body>
55
56 </body>
57 </html>
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6
7 <script type="text/javascript">
8
9 console.info("10"+1); //111
10 //当进行减法运算时，会自动完成转换
11 console.info("10"-1); //9
12
13 //根据数字来进行排序的函数
14 function sortByNum(a,b){
15 return a - b ;
16 }
17
18 var as = [1,2,11,33,12,190];
19 //对应js而言，默认是按照字符串排序
20 as.sort();
21 console.info(as); // [1, 11, 12, 190, 2, 33]
22
23 as.sort(sortByNum);
24 console.info(as); //[1, 2, 11, 12, 33, 190]
25
26 //根据数字来进行排序的函数
27 function sortByNum2(a,b){
28 return parseInt(a) - parseInt(b) ;
29 }
30 var as2 = [1,2,"11px",33,"12px",190];
31 as2.sort(sortByNum2);
32 console.info(as2); //[1, 2, "11px", "12px", 33, 190]
33 </script>
34
35 </head>
36 <body>
37
38 </body>
39 </html>
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6
7
8
9 </head>
10 <body>
11 <div id="person"> </div>
12 <script type="text/javascript">
13
14 function Person(name,age){
15 this.name = name ;
16 this.age = age ;
17 }
18
19 var p1 = new Person("Leon",39);
20 var p2 = new Person("John",23);
21 var p3 = new Person("Ada",41);
22 var ps = [p1,p2,p3];
23 ps.sort();
24 console.info(ps); //[Person { name="Leon", age=39}, Person { name="John", age=23}, Person { name="Ada", age=41}]
25
26 /**
27 * 使用sortByName sortByAge这两个方法来处理排序，带来的我呢体是需要为每一个属性都设置一个函数
28 * 显然不灵活
29 * 但是如果通过函数的返回值调用就不一样了
30 */
31 function sortByName(obj1 , obj2){
32 if(obj1.name > obj2.name ){
33 return 1;
34 }else if(obj1.name == obj2.name ){
35 return 0 ;
36 }else{
37 return -1 ;
38 }
39 }
40
41 ps.sort(sortByName);
42 console.info(ps); //[Person { name="Ada", age=41}, Person { name="John", age=23}, Person { name="Leon", age=39}]
43
44 function sortByAge(obj1 , obj2){
45 return obj1.age - obj2.age;
46 }
47 ps.sort(sortByAge);
48 console.info(ps); //[Person { name="John", age=23}, Person { name="Leon", age=39}, Person { name="Ada", age=41}]
49
50
51 //改造方法
52 function sortByProperty(propertyName){
53 var sortFun = function(obj1 , obj2){
54 if(obj1[propertyName] > obj2[propertyName]){
55 return 1 ;
56 }else if(obj1[propertyName] == obj2[propertyName]){
57 return 0 ;
58 }else{
59 return -1 ;
60 }
61 }
62 return sortFun;
63 }
64
65 ps.sort(sortByProperty("age"));
66 console.info(ps); //[Person { name="John", age=23}, Person { name="Leon", age=39}, Person { name="Ada", age=41}]
67
68 ps.sort(sortByProperty("name"));
69 console.info(ps); //[Person { name="Ada", age=41}, Person { name="John", age=23}, Person { name="Leon", age=39}]
70
71 function show(){
72 var p = document.getElementById("person");
73 for(var i = 0 ; i < ps.length ; i ++){
74 p.innerHTML += ps[i].name + " , " + ps[i].age + "<br/>";
75 }
76 }
77
78 show();
79 </script>
80 </body>
81 </html>
时间： 2024-10-08 09:46:45