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    <p>My guess is that you haven't assigned a <code>Body</code> object to <code>person.body</code> anywhere.</p> <p>All objects in Objective-C are allocated on the heap. All those asterisks denote that the variables are pointers, which are mere numbers pointing to memory locations where the objects live. When you declare a property that holds an object, all you are really doing is creating a place to store a pointer to the object. You aren't creating the object itself.</p> <p>So somewhere (most likely in <code>Person</code>'s designated initialiser), you'll want to actually create a <code>Body</code> object and assign it to the <code>body</code> property.</p> <p>If you <em>don't</em> do this, then the memory location will remain at <code>0</code>, which is equivalent to <code>nil</code>. When you chain the assignment here:</p> <pre><code>int feet = person.body.feet = 2; </code></pre> <p>...you're assigning <code>2</code> to both <code>feet</code> and <code>person.body.feet</code>, but since <code>person.body</code> is <code>nil</code>, the setter message to it is ignored. When later you try to log <code>person.body.feet</code>, again, it will be <code>nil</code> and return <code>nil</code>/<code>0</code>.</p> <p><strong>Edit:</strong> Having looked at your update, yes, this is your problem.</p> <p>This line does not create a <code>Body</code> object:</p> <pre><code>Body *body; </code></pre> <p>It creates an instance variable for a <em>pointer to</em> a <code>Body</code> object.</p> <p>This line does not create a <code>Body</code> object:</p> <pre><code>@property (assign) Body *body; </code></pre> <p>It declares a property, which is syntactic sugar for getter and setter method declarations.</p> <p>This line does not create a <code>Body</code> object:</p> <pre><code>@synthesize body; </code></pre> <p>It synthesises your previously declared property by creating the getter and setter methods.</p> <p>You need to actually create and initialise a <code>Body</code> object and then assign it to your <code>Person</code> object's <code>body</code> property. For instance:</p> <pre><code>- (id)init { if (self = [super init]) { self.body = [[Body alloc] init]; } return self; } </code></pre> <p>Also, as you aren't using ARC, you should almost certainly declare that property to be <code>retain</code> not <code>assign</code>, and release it in your <code>Person</code>'s <code>dealloc</code> method.</p>
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    1. COFantastic answer !! I have but the init method in my Person.m file and all works well. What I was trying to do with this experiment was not to create a actual body object in main and your answer has achieved this brilliantly. Just one point - because the self.body has been allocated memory would it be released when I release the person object ??
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    2. CONo, not unless you are using ARC. Any method with `new`, `alloc`, `retain` or `copy` in the name confers ownership upon you and it's your responsibility to release it. Use the `dealloc` method for that. Furthermore, if you declare a property as `retain` or `copy`, the retain count will go up for any object assigned to it. You should read the [Memory Management guide](https://developer.apple.com/library/mac/#documentation/cocoa/conceptual/memorymgmt/) Apple provide for more details. If possible, switch to using ARC, as it takes a lot of the work off your hands.
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