错哪了呀，为什么答案出来是0？
#include <stdio.h>
int func(int a)
{
int b;
switch(a)
{
case 1: b=39;
case 2: b=20;
case 3: b=17;
default: b=0;
}
return b;
}
int main()
{
printf("%d\n",func(3));
return 0;
}
#include <stdio.h>
int func(int a)
{
int b;
switch(a)
{//把每一个都加上return就可以了，输出17
case 1: return b=39;
case 2: return b=20;
case 3: return b=17;
default: return b=0;
}
}
int main()
{
printf("%d\n",func(3));
return 0;
}