C语言 函数指针的应用

 1 #include"stdio.h"
 2 
 3 char myFun(char ch)
 4 {
 5     printf("myFun is called, your char is %c.\n",ch);
 6     return ‘w‘;
 7 }
 8 
 9 void main()
10 {
11     char temp;
12 
13     char (* funPtr)(char);    //定义一个函数指针
14     funPtr=myFun;            //将myFun的地址给funPtr
15     temp=funPtr(‘s‘);        //此时可以认为对funPtr的调用就等同于对myFun的调用
16 
17     printf("return value: %c\n",temp);
18     printf("size of myFun: %d\n",sizeof(funPtr));
19 }
结果：

myFun is called, your char is s.
return value: w
size of myFun: 4

 1 #include"stdio.h"
 2 
 3 typedef struct{
 4     char (* funPtr)(char);    //定义一个函数指针
 5 }myFunStruct_t;
 6 
 7 char myFun(char ch)
 8 {
 9     printf("myFun is called, your char is %c.\n",ch);
10     return ‘w‘;
11 }
12 
13 void main()
14 {
15     char temp;
16 
17     myFunStruct_t myFunStruct;
18     myFunStruct.funPtr=myFun;        //将myFun的地址给funPtr
19     temp=myFunStruct.funPtr(‘s‘);    //此时可以认为对funPtr的调用就等同于对myFun的调用
20 
21     printf("return value: %c\n",temp);
22     printf("size of myFunStruct_t: %d\n",sizeof(myFunStruct_t));
23 }
结果：

myFun is called, your char is s.
return value: w
size of myFunStruct_t: 4

 1 #include"stdio.h"
 2 
 3 typedef void (* funInPtr_t)(void);        //函数原型定义
 4 typedef void (* funOutPtr_t)(void);
 5 
 6 typedef struct{
 7     funInPtr_t funInPtr;
 8 }myInStruct_t;
 9 
10 typedef struct{
11     funOutPtr_t funOutPtr;
12     myInStruct_t myInStruct;
13 }myOutStruct_t;
14 
15 void myInFun(void)
16 {
17     printf("myInFun\n");
18 }
19 
20 void myOutFun(void)
21 {
22     printf("myOutFun\n");
23 }
24 
25 void main()
26 {
27     myOutStruct_t myOutStruct;
28     myOutStruct.funOutPtr=myOutFun;
29     myOutStruct.myInStruct.funInPtr=myInFun;
30     
31     myOutStruct.funOutPtr();                    //外层函数
32     myOutStruct.myInStruct.funInPtr();            //内层函数
33 
34     printf("size of myInStruct_t: %d\n",sizeof(myInStruct_t));
35     printf("size of myOutStruct_t: %d\n",sizeof(myOutStruct_t));
36 }
结果：

myOutFun
myInFun
size of myInStruct_t: 4
size of myOutStruct_t: 8