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POShifting elements in an array in C -- pointer-based
 

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  1. POShifting elements in an array in C -- pointer-based
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    <p>So I'm trying to learn C right now, and I have two functions: one that shifts elements in an array:</p> <pre><code>void shift(int a[], int n) { int i; for(i = 0; i != n-1; i++){ a[i] = a[i+1]; } } </code></pre> <p>and a version of the same function, except pointer-based:</p> <pre><code>void pointer_shift(int *a[], int n) { int i; for (i = 0; i != n - 1; i++) { *a[i] = *a[i + 1]; } } </code></pre> <p>I don't know whether the pointer-based version is correct or not, but I guess my most important question is how I'm supposed to actually test that both/either work. Besides the definition of these two functions, I have:</p> <pre><code>#include &lt;stdio.h&gt; void shift(int a[], int n); void pointer_shift(int *a[], int n); int main(void) { printf("Begin execution of testing Problem 1\n"); int a1[] = {100, 101, 102}; int i; for(i = 0; i&lt;3;i++) printf("Before Shift: " "%d\n", a1[i]); //shift(a1, 3); pointer_shift(&amp;a1, 3); for(i = 0; i&lt;3;i++) printf("After Shift In Main: " "%d\n", a1[i]); return 0; } </code></pre> <blockquote> <p>shift(a1, 3)</p> </blockquote> <p>works fine, but I, for the life of me, can't figure out how to correctly test pointer_shift. </p> <p>I get two errors; one is that in the line</p> <blockquote> <p>pointer_shift(&amp;a1, 3)</p> </blockquote> <p>I am passing argument 1 from an incompatible pointer type. The other error is indecipherable, but I was hoping the problem would be obvious enough that someone would be able to help me. So... how to test my two functions in my main?</p> <p>Thanks!</p>
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    1. USRyan Yu
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    1. COThis is off topic - but when you use C++11, it is better to use std::array over pointers to array.
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