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POchar array is crashing my stack structure. Did I declare something wrong?
 

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  1. POchar array is crashing my stack structure. Did I declare something wrong?
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    <p>I'm trying to gain an intuition for how the stack structure works but for some reason any time I try to print from <code>charElements</code>, my program crashes and I have NO clue why. This is the error I keep getting: (its at a breakpoint) <code>while (i-- &amp;&amp; *p)</code>. But I have no clue whats wrong with how I declared everything. Any thoughts?</p> <pre><code>#include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;string.h&gt; #include &lt;math.h&gt; typedef struct Stack { int capacity; // max # of elements the stack can hold int size; // current size of the stack int *elements; // the array of elements char *charElements; // the array of chars }Stack; Stack * createStack(int maxElements) { // Create a Stack Stack *S; S = (Stack *)malloc(sizeof(Stack)); // Initialise its properties S-&gt;charElements = (char *)malloc(sizeof(int)*maxElements); S-&gt;elements = (int *)malloc(sizeof(int)*maxElements); S-&gt;size = 0; S-&gt;capacity = maxElements; /* Return the pointer */ return S; } int main() { Stack *S = createStack(60); char registerNames[63] = {"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"}; // if the user input a a string S-&gt;elements[S-&gt;size++] = 1; S-&gt;elements[S-&gt;size++] = 2; S-&gt;elements[S-&gt;size++] = 3; S-&gt;charElements[S-&gt;size++] = *registerNames; printf("%d \n", S-&gt;elements[0]); printf("%d \n", S-&gt;elements[1]); printf("%d \n", S-&gt;elements[2]); printf("%d \n", S-&gt;size); printf("%s \n", S-&gt;charElements[3]); system("pause"); return 0; } </code></pre>
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    1. USellie0414
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    1. COI can see no `while (i-- && *p)` in your code
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      1. POchar array is crashing my stack structure. Did I declare something wrong?
      1. USJohn Dvorak
    2. COFYI: in C, don't cast the result from `malloc` (i.e. you should use `S = malloc(...)` instead of `S = (Stack *)malloc(...)`. See also this question: http://stackoverflow.com/questions/605845/do-i-cast-the-result-of-malloc
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      1. USnneonneo
    3. CO`printf("%s")` expects a `char*`, you're giving it a single `char`. Other things you should look into: zero out `charElements` after allocating it. You're overallocating `charElements` - try `malloc(sizeof(char) * maxElements)` instead. And don't cast the return value of `malloc`.
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      1. USDCoder
 

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