找出c程序的输出

Question

#include<stdio.h>
void compute(int);
int cube(int);
int main( )
{
        compute(3);
}
void compute(int in)
{
        int res=0,i;
        for(i=1;i<=in;i++);
        {
                res=cube(i);
                printf("%d %d",res,i);
        }
}
int cube(int n)
{
        return (n*n*n);
}

~
output : 64 4

How does it happen ?

Answer 1

分号在您for行的结尾。

Answer 2

由于您的for行上使用了分号，因此该语句将i递增，直到它不小于等于3的3，然后运行。

Answer 3

Since you are using C99, you may want to get into the habit of declaring the variable controlling a for loop inside the for statement itself.

    for (int i=1; i<=in; i++);
    {
        /* i is not in scope here */
    }

And, now that I've written that, the idiomatic way to write a loop is to start at 0 and test with <

    for (int i=0; i<in; i++);
    {
        /* i is not in scope here */
    }