Having difficulty understanding func(&_) in c

Question

Can someone please explain me the purpose of func(&_) and void? I am not sure how the whole program works.

    void func(int *xp);

    int
    main(void)
    {
        int x, y;

        x = 5; 
        func(&x);
        y = x-3;
        func(&y);
        printf("%4d%4d\n", x, y);
        return(0);
    }

    void
    func(int *xp)
    {
        int y;

        y = *xp * 2;
        *xp = y - 3;
    }

Look into the reference & (no pun intened) dereference operators. `func` takes a pointer to an int, `&x` results in the assignment `int* xp = &x`, so that `xp` is a pointer to `x`. — HennyH, May 23 '14 at 05:59
This is a particularly contrived example which shows **a** way to use pointers, but doesn't explain what problem pointers are there to solve. — dreamlax, May 23 '14 at 06:00
thanx HennyH. that made a lot more sense and just figured it out. thanx a lot — user3667675, May 23 '14 at 06:04

score 0 · Answer 1 · answered May 23 '14 at 07:43

0

Your function demands a pointer argument. If you want to pass a non-pointer variable to that function call, you must provide it's address, using the & notation.

answered May 23 '14 at 07:43

Andro

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Having difficulty understanding func(&_) in c

1 Answers1