空指针，可能是某个参数没有默认值 空指针异常，指的是你这个引用对象没有成功赋值，即为空你应该定义个函数指针，如int(fun*)(void );VC调试时按Alt+8、Alt+7、Alt+6和Alt+5,打开汇编窗口、堆栈窗口、内存窗口和寄存器窗口看每句C对应的汇编、单步执行并观察相应堆栈、内存和寄存器变化，这样过一遍不就啥都
(middle) fp1 is → (right, nothing) → (left) a pointer to → (right) a function that takes an int → (left) and returns a pointer to → (right) an array of 10 → (left) void pointers. 连起来就是:fp1 is a pointer to a function that takes an int and returns a pointer to ...
理解C中的函数指针 ;// Function pointervoidtest1(intage){printf("test1:%d\n\n",age);}voidforeachNums(int*nums,intlen,intFunc func){inti;for(i=0; i<len; i++) {intnum = nums[i];func(num);// call the function through its pointer}}voidprintNum(intnum){printf("value=%d\n",num)...
**/printf("在swap函数中:\n"); printf("指针x指向的地址为%p,值为%d,指针本身的地址为%p\n", x, *x, &x); printf("指针y指向的地址为%p,值为%d,指针本身的地址为%p\n", y, *y, &y);inttmp = *x;*x = *y;*y =tmp; }intmain(void) {intx =3, y =5; printf("在main函数中:\...
assigned in setCallback function */ } 使用gcc编译时,gfnPtr()在64位suse linux上崩溃。但是它成功调用了gfnPtr()VC6和SunOS。 但是,如果我按如下所示更改功能,则它可以成功运行。 void setCallback(const void *fnPointer) { int i; // put any statement here gfnPtr = *((FN_GET_VAL*) (&fnPo...
C 指针的小小实验 更新: 空白指针,也被称为通用指针,是一种特殊类型的指针,可以指向任何数据类型的对象! 空白指针像普通指针一样被声明,使用void关键字作为指针的类型。 The void pointer, also known as the…
利用typedef定義一個predicate型態的function pointer,傳入為int,傳出為int,雖然不一定得自行用typedef定義,但function pointer很容易寫成很複雜很難懂的程式,所以建議用typedef重新定義。 21行 void print_array(int *beg, int *end, predicate fn) { 宣告print_array最後一個參數為predicate這個function pointer型態,可...
#include<stdio.h>typedefint(FUNC)(int);inttest(inti){returni*i;}voidf(){printf("Call f()...\n");}intmain(){FUNC*pt=test;void(*pf)()=&f;printf("pf = %p\n",pf);printf("f = %p\n",f);printf("&f = %p\n",&f);pf();(*pf)();printf("Function pointer call: %d\n"...
the resultsofaos are: result=15.000000 result=5.000000 result=50.000000 result=2.000000 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 时间不早了,该回去睡觉了~ 引用: Function pointer tutorial....
voidmultiplication_message(void) { printf("%s = %d\n","multiplication",arithmatic_result); } //Create typedef of pointer to function 2D array typedefvoid(*const afEventHandler[Laststate][LastSubState])(void); //2D array of function pointer ...