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    <p>There are three cases to consider:</p> <ul> <li><p>use of <code>someObject.something</code></p></li> <li><p>use of <code>self-&gt;something</code></p></li> <li><p>use of <code>otherObject-&gt;something</code></p></li> </ul> <p><code>someObject.something</code> is the <em>dot syntax</em>. It is exactly equivalent to <code>[someObject something]</code> in terms of behavior. It is a method call. Note that <code>something</code> does not have to be declared via an <code>@property</code>. That is, <code>someArray.count</code> or <code>someString.length</code> are both syntactically valid.</p> <p><code>self-&gt;something</code> is accessing an ivar directly. It is a very rarely used syntax; rare is in <em>pretty much never</em>. Instead, just access the ivar directly using <code>something =</code> or <code>[something doSomething]</code>. No need for the <code>-&gt;</code>.</p> <p><code>otherObject-&gt;something</code> is grubbing around <code>otherObject</code>'s instance variables directly. Bad programmer. No donut. Don't do that. It breaks encapsulation and leads to extremely fragile, hard to maintain, code.</p> <hr/> <p>A note on <code>@property</code> declarations. If you have:</p> <pre><code> @property (atomic, strong, readonly) SomeClass *foo; </code></pre> <p>And if you let the compiler automatically <code>@synthesize</code> everything, it will create an instance variable named <code>_foo</code>.</p> <p>You should use direct access in your <code>init</code> and <code>dealloc</code> methods, but -- typically, though not always -- use the setter/getter everywhere else. I.e. in your <code>init</code> you would do <code>_foo = [SomeClass someClassWithSomeMagicValue:42]</code> (assumes ARC, so no <code>retain</code> needed). Everywhere else, you would do <code>[[self foo] castMagic];</code>.</p>
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    1. PODifference between var->myProperty and var.myProperty
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    1. COThe last two cases are the same case.
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    2. CO@newacct Not quite; the 2nd case does not break encapsulation in that it is accessing the instance variable of the instance that is executing the method. In the 3rd case, the code would be accessing the iVar of some *other* object, breaking encapsulation.
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    3. CObut that's not a language concept. It's just a programming style issue.
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