Question

Is making a iVar public in objective-C defeats the purpose of encapsulation?

@interface SampleClass{
@public
int totalRecords;
}

Answer 1

In short, yes.

Direct access of ivars means that there is no way that subclasses or future versions of your SampmleClass can ever implement any kind of customized behavior when totalRecords is read or written.

This is why access to object state is through methods everywhere but in the implementation of the class itself (and, even then, it is mostly through methods).