Thread: whats the problem

I tried to use pointer with a function but I guess I am missing out on something

Code:

#include<stdio.h>
int add(int *a,int *b){
    int *c,*d;
    *c = *c+1;
    *d = *d-1;

};
main()
{
    //int Fun;
    int num1,num2;
    num1 = 10;
    num2 = 10;
    add(&num1,&num2);
    printf("    %i        %i   " ,num1,num2);

}

and this one too

Code:

#include<stdio.h>
void add(int *a){
    int *c;
    c = c+1;
};
main()
{
    int num1;
    num1 = 10;
    add(&num1);
    printf("    %i " ,num1);
    getch();

}

Originally Posted by laserlight

In your first program, you forgot to make your pointers point to an object before dereferencing them.

In your second program, you incremented c, but that is not useful because the pointer does not point to the first element in an array, and besides, you only changed the local pointer.

dont understand , need an example or the code debugged

Originally Posted by Salem

Perhaps you should stop declaring local pointer variables that point nowhere, and do something like this, with the parameter

*a = *a + 1;

an example please

tried that and worked

Code:

#include<stdio.h>
void add(int *c){
    
    *c = *c+1;
};
main()
{
    int num1;
    num1 = 10;
    add(&num1);
    printf("    %i " ,num1);
    getch();

}

Originally Posted by laserlight

Here is an example:

Code:

#include<stdio.h>

int add(int *a, int *b)
{
    *a += 1;
    *b += 2;
}

int main(void)
{
    int num1, num2;
    num1 = 10;
    num2 = 10;
    add(&num1, &num2);
    printf("%d %d\n", num1, num2);
    return 0;
}

thank you so much