[RESOLVED] A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?
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  1. #1
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    [RESOLVED] A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?

    Hello,

    Code:
    int arr[10];
    int* p = arr;
    int (*p2)[10] = &arr;
    So, pointer p is a pointer to an array, I can use it to access elements of arr as in *(p+5).

    Pointer p2 is a pointer to an array of ten integers. What is it for, how can I use it to access elements of arr?

    Thank you.

  2. #2
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    Re: A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?

    In this case, there probably is not much use for p2. However, if you were dealing with a 2D array, then it could become useful.
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    Re: A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?

    Quote Originally Posted by vincegata View Post
    So, pointer p is a pointer to an array, I can use it to access elements of arr as in *(p+5).
    Strictly, p is a pointer to the first element of an array.
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    Re: A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?

    Strictly, p is a pointer to the first element of an array.
    true, but in the way the 2nd pointer is defined in the OP, it's a pointer to an array of (an array of) 10 ints (and not a pointer to (an array of) ints). and p2[0] points to the first of said arrays of 10 ints.
    p2[1] would point to another array of 10 ints.

    you can access the first int - element as p2[0][0] (=return the 1st int of the 1st array of 10 ints).
    or alternatively you could (for the first element) also write this as: (*p2)[0] (the parens are significant here. or you'll get *(p2[0]))

  5. #5
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    Re: A pointer to an array: int* p = arr; vs. int (*p2)[10] = &arr; ?

    I see, thanks guys for all responses.

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