Summary 75 helpful. Finish out this class by adding the synthesize statement to the imple- mentation file: @synthesize firstName, lastName, parent; We aren't limited to declaring our object lifetime intentions to properties. You can prefix variable declarations with lifetime hints like __strong , __weak , __unsafe_ unretained , and __autoreleasing . By default, variables are declared with the __strong lifetime hint. Automatic Reference Counting will be used by default in every sample throughout the remainder of the book. This should not only make the samples easier to read and experiment with, but should get you used to Apple's new recommendation for development on OS X Lion. Did You Know? Strong Versus Weak References As you saw in the preceding code, we can choose to declare objects with strong refer-