Thread: pass by reference by inner function in C

I intend to change the value of count by function B(), but I failed...can't find the reason why...here's my code...

Code:

void B(int *count)
{
     do{
        *count = *count + 1;
     }while(condition);
}

void A(int *count)
{
    *count = 0;
    B(count);
}

int main()
{
    int count;
    A(&count);
    return 0;
}

How do you know, you never check the value of count after you call A. What is condition?

Originally Posted by Subsonics

How do you know, you never check the value of count after you call A. What is condition?

Well, the code I provided is a simplified version. I use printf() function to check in reality.

Originally Posted by shanwu

Well, the code I provided is a simplified version. I use printf() function to check in reality.

Everything should be made as simple as possible but not simpler.

Your code does not make sense, what is "condition"? Is it ever updated? Where is it declared?

Originally Posted by laserlight

This is a test program based on your code:

Code:

#include <stdio.h>

void B(int *count)
{
    *count = *count + 1;
}
 
void A(int *count)
{
    *count = 0;
    B(count);
}
 
int main(void)
{
    int count;
    A(&count);
    printf("%d\n", count);
    return 0;
}

I ran it and it prints 1. Therefore, contrary to your assertion in post #1, there is no problem with your code where changing the value of count in function B is concerned.

thank you very much. I will try to find other possible mistakes... thanks

Thus your problem is in 'condition' which you have left us guessing about so far.