strcpy throws memory exception
<pre><code>#include&lt;stdio.h&gt;
#include&lt;string.h&gt;
#include&lt;iostream.h&gt;

using namespace std;

int main()
{
    const char *a="hello";
    char *b;
    strcpy(b,a);
     cout&lt;&lt;b;


    return 0;
}
</code></pre>

<p>This code theows memory exception . why ?</p>
