C语言 未曾知晓 获取函数地址,利用这个地址调用函数

#include <stdio.h>

typedef unsigned short	UNSIGNED16;
typedef unsigned char   UNSIGNED8;
typedef UNSIGNED16 (*DEMO_CYCLE)(void);

static UNSIGNED16 lp_demo(void);
static UNSIGNED16 ap_demo(void);
static UNSIGNED16 md_demo(void);
static UNSIGNED16 mixed_demo(void);

DEMO_CYCLE 	p_demo_cycle = NULL;
DEMO_CYCLE 	p_demo_cycle_group[4] = {lp_demo, ap_demo, md_demo, mixed_demo};
UNSIGNED8 	demo_type;

static UNSIGNED16 lp_demo(void)
{
printf("lp_demo执行这里\n");
return 0;
}
static UNSIGNED16 ap_demo(void)
{
printf("ap_demo执行这里\n");
return 0;
}
static UNSIGNED16 md_demo(void)
{
printf("md_demo执行这里\n");
return 0;
}
static UNSIGNED16 mixed_demo(void)
{
printf("mixed_demo执行这里\n");
return 0;
}

int main(int argc, char *argv[])
{
UNSIGNED16  result = 0;
printf("%d\n",demo_type);
//获取函数地址
p_demo_cycle = p_demo_cycle_group[demo_type];
//利用函数地址调用函数
result = (*p_demo_cycle)();
return 0;
}