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    <p>(Un)fortunately, the asterisk <code>*</code> has many <em>different</em> meanings depending on context. So, let's look at the relevant ones. Let us write <code>T</code> for some arbitrary type (say <code>int</code>):</p> <pre><code>T x; // variable of type x, stored somewhere in memory T * pt; // a pointer to a variable of type x -- doesn't have a value just yet pt = &amp;x; // the value of pt is now the address of the variable x </code></pre> <p>So far so good. We have used the asterisk to designate a new <em>type</em>, namely <code>T*</code>, which is a "pointer to <code>T</code>".</p> <p>But what do we do with a pointer? We can <em>dereference</em> it to get to the value of the variable <em>at the address pointed to by the pointer</em>:</p> <pre><code>T y; // another variable of type T y = *pt; // equivalent to y = x; *pt = 81; // equivalent to x = 81; </code></pre> <p>So, if the asterisk is part of the typename, then it designates a pointer type. If it comes before a variable name (which is itself of pointer type), then it dereferences the pointer.</p> <p>[Clarification:] <em>In C</em>, pointers naturally go hand-in-hand with the "address-of" operator <code>&amp;</code>, which is used to actually obtain a pointer to something. <em>In Obj-C, a pointer is obtained as the result of object allocation (+ initailization):</em> <code>T * pt = [T new];</code></p> <p>Beware that Obj-C offers an alternative syntax to the traditional C and C++ pointer syntax, so you may encounter pointers in other guises.[/Clarification]</p> <p>(The asterisk can also be used as a binary operator of course, so you can have something like this: <code>int x = 5; int * p = &amp;x; int y = *p * *p;</code>.)</p>
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    1. POIs there an Ultimate Guide to Pointers in Objective-C?
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    1. COHe's talking about Obj-C. It's totally different. All objects (instances of classes) are pointers there ...
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    2. COAnd Obj-C has no reference types like C++. It is pure C with OO, Smalltalk-like, extensions.
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    3. CO@Rudy: I'm not mentioning references at all. (Indeed, in C++ a dereference would be of type `T&`, but I'm not saying this here.) Tim: Isn't Objective-C a superset of C? All the C pointer mechanics should apply there as well? If not I'll delete this post.
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