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    <blockquote> <p>whats wrong with the code.</p> </blockquote> <p>Everything except <code>int i;</code></p> <p>The second line attempts to convert an integer to a pointer. In special circumstances, you could force that past the compiler with <code>reinterpret_cast</code>; but the program would only behave correctly if the integer somehow contained a valid pointer value. (<strong>UPDATE</strong>: the question has now been edited to take the address of <code>i</code> instead; so this line is no longer wrong).</p> <p>The third line attempts to delete invalid memory using an invalid pointer type.</p> <blockquote> <p>What it should be.</p> </blockquote> <p>Something else. Without knowing what you want to do, it's impossible to say. Perhaps you want:</p> <pre><code>int i; void * ptr = &amp;i; // Points to `i`, losing type information. </code></pre> <blockquote> <p>Operator <code>delete</code>, applied to <code>void*</code> argument.</p> </blockquote> <p>That's always wrong. You must only <code>delete</code> an object you previously allocated with <code>new</code>; and the pointer must be to the correct type.</p> <p><sub>(or to a base class, if it's a class type with a virtual destructor)</sub></p> <p>So the following would be correct; but pointless unless you have a good reason for dynamic allocation:</p> <pre><code>int * ptr = new int; delete ptr; </code></pre> <p>And of course, if you're writing code that should be robust against memory leaks and runtime errors, you should manage all dynamic memory using <a href="http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization" rel="noreferrer">RAII</a> types such as containers and smart pointers. So, if you need to a dynamic object, you should do:</p> <pre><code>std::unique_ptr&lt;int&gt; ptr(new int); </code></pre> <p>if you want a to delete it at the end of the current scope or move it into another scope; or</p> <pre><code>auto ptr = std::make_shared&lt;int&gt;(); </code></pre> <p>if you want to share ownership between more than one scope. In either case, the pointers will delete the object automatically once you've finished with it.</p>
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    1. POdeleting a void pointer using delete operator
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    1. COint *i = new int; void *ptr = i; delete ptr; Is this ok ?
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    2. CO@Anand: No, because you must use `int*` to delete an `int`. Without the correct type information, `delete` gives undefined behaviour.
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    3. COthen in this case how to delete ptr ?
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