 <p>Objective-C is C. The primitive (what I would call <em>scalar</em>) data types are all numbers and are completely defined by the language; you cannot add to them (though you can rename them using <code>typedef</code>. The corresponding literals, such as <code>1</code> and <code>"hello"</code>, are also part of C.</p> <p>Similarly, literals like <code>@"howdy"</code> and <code>@[@"howdy"]</code>, though defined by Objective-C rather than C, are part of the language and you cannot change or add to them, as the literal syntax is built into the language.</p>