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POWhy this code doesn't allocate memory in C?
 

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  1. POWhy this code doesn't allocate memory in C?
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    <p>Updated question is here</p> <p><a href="https://stackoverflow.com/questions/828108/please-help-me-to-solve-this-memory-allocation-problem">Memory allocation problem in HashTable</a></p> <p>I'm working on making a HashTable in C. This is what I've done. I think I'm going on a right path but when I'm trying to </p> <p><strong>main.c</strong></p> <pre><code>HashTablePtr hash; hash = createHashTable(10); insert(hash, "hello"); insert(hash, "world"); </code></pre> <p><strong>HashTable.c</strong></p> <pre><code> HashTablePtr createHashTable(unsigned int capacity){ HashTablePtr hash; hash = (HashTablePtr) malloc(sizeof(HashTablePtr)); hash-&gt;size = 0; hash-&gt;capacity = capacity; ListPtr mylist = (ListPtr)calloc(capacity, sizeof(ListPtr)); /* WHY IT DOESN'T ALLOCATE MEMORY FOR mylist HERE?? */ mylist-&gt;head = NULL; mylist-&gt;size = 0; mylist-&gt;tail = NULL; hash-&gt;list = mylist; return hash; </code></pre> <p>ListPtr is a LinkedList ptr</p> <p><strong>List.h</strong></p> <pre><code>typedef struct list List; typedef struct list * ListPtr; struct list { int size; NodePtr head; NodePtr tail; }; ... ... </code></pre> <p><strong>HashTable.h</strong></p> <pre><code> typedef struct hashtable * HashTablePtr; typedef struct hashtable HashTable; struct hashtable { unsigned int capacity; unsigned int size; ListPtr *list; unsigned int (*makeHash)(unsigned int, void *); }; ... ... </code></pre> <p>When I run my debugger, I see no memory being allocated to myList. In above example, my attempt is to make it an array of 10 lists.</p> <p>Please help me to solve this.</p> <p>I'm not that expert in C, if that helps.</p>
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    1. COThe code you pasted has a number of inconsistencies - an extra ) in createHashTable, more arguments in the call to createHashTable than it actually takes. Is this the same code that you're running? It's better to copy-and-paste than retype, as you might introduce (or fix) errors in the process...
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    2. COI think a lot of your problems will become visible if you don't hide your pointers. That is, get rid of ListPtr and NodePtr what not.
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    3. COoops! I just wanted to make it look cleaner, and screwed it up. I'm sorry.
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