C语言 递归函数 传参问题

Question

#include

int x = 0;
int function(int num);

int main()
{
int num = 0;
int y = function(num);
printf("%d\n",num);

return 0;

}

int function(int num)
{
//printf("%d ",num);
//printf("%d ",x);
while(x<100)
{
x++;
num+=x;
function(num);
//printf("%d ",num);
//printf("%d ",x);

}

return num;

}

为什么最后会输出num的值为0

Answer 1

#include <stdio.h>

int x = 0;
int function(int num);
int main()
{
int num = 0;
int y = function(num);
printf("%d\n",y);
return 0;
}
int function(int num)
{
//printf("%d ",num);
//printf("%d ",x);
if(x<100)
{
x++;
num+=x;
return function(num);
//printf("%d ",num);
//printf("%d ",x);
}

return num;
}