函数指针_01

#include<stdio.h>
int sum (int ,int );
int main(int argc, char *argv[])
{
    printf("hello world\n");
    //函数指针
    int (*func_ptr)(int,int) = sum;
    printf("%d\n",func_ptr(5,1));
}
int sum(int a ,int b){
    return a + b;
}

猜猜结果是?