#include <stdio.h>

void echo(void) {
printf("===========echo===================\n");
}

void echo1(void) {
printf("===========echo1===================\n");
}

long sum(int a,long b){
return a+b;
}


int main(){

// 定义函数指针
void (*p) (void);

long (*p1) (int,long);

// void *func(int *a)
void *(*p3)(int *);

p = echo;
p();
p = echo1;
p();

p1 = sum;
long result = p1(5,100);
printf("===========result=%d\n",result);

return 1;
}