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copied!<p>The declaration and initialization</p> <pre><code>char *array = "One good thing about music"; </code></pre> <p>declares a pointer <code>array</code> and make it point to a constant array of 31 characters.</p> <p>The declaration and initialization</p> <pre><code>char array[] = "One, good, thing, about, music"; </code></pre> <p>declares an array of characters, containing 31 characters.</p> <p>And yes, the size of the arrays is 31, as it includes the terminating <code>'\0'</code> character.</p> <hr> <p>Laid out in memory, it will be something like this for the first:</p> <pre> +-------+ +------------------------------+ | array | --> | "One good thing about music" | +-------+ +------------------------------+ </pre> <p>And like this for the second:</p> <pre> +------------------------------+ | "One good thing about music" | +------------------------------+ </pre> <hr> <p>Arrays decays to pointers to the first element of an array. If you have an array like</p> <pre><code>char array[] = "One, good, thing, about, music"; </code></pre> <p>then using plain <code>array</code> when a pointer is expected, it's the same as <code>&array[0]</code>.</p> <p>That mean that when you, for example, pass an array as an argument to a function it will be passed as a pointer.</p> <p>Pointers and arrays are <em>almost</em> interchangeable. You can not, for example, use <code>sizeof(pointer)</code> because that returns the size of the actual pointer and not what it points to. Also when you do e.g. <code>&pointer</code> you get the address of the pointer, but <code>&array</code> returns a pointer to the array. It should be noted that <code>&array</code> is <em>very</em> different from <code>array</code> (or its equivalent <code>&array[0]</code>). While both <code>&array</code> and <code>&array[0]</code> point to the same location, the types are different. Using the arrat above, <code>&array</code> is of type <code>char (*)[31]</code>, while <code>&array[0]</code> is of type <code>char *</code>.</p> <hr> <p>For more fun: As many knows, it's possible to use array indexing when accessing a pointer. But because arrays decays to pointers it's possible to use some pointer arithmetic with arrays.</p> <p>For example:</p> <pre><code>char array[] = "Foobar"; /* Declare an array of 7 characters */ </code></pre> <p>With the above, you can access the fourth element (the <code>'b</code>' character) using either</p> <pre><code>array[3] </code></pre> <p>or</p> <pre><code>*(array + 3) </code></pre> <p>And because addition is <a href="http://en.wikipedia.org/wiki/Commutativity" rel="noreferrer">commutative</a>, the last can also be expressed as</p> <pre><code>*(3 + array) </code></pre> <p>which leads to the fun syntax</p> <pre><code>3[array] </code></pre>

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