Question

I am checking if an object I am getting back from the NSURLConnectionDataDelegate is the same object that I originally created. What I have been doing is:

// TESTING TO SEE IF THE RETURNED OBJECT IS THE SAME ONE I CREATED
if(connection == [self connectionPartial]) {

But was just curious is this is the same as doing:

if([connection isEqual:[self connectionPartial]]) {

Answer 1

It’s not the same.

if(connection == [self connectionPartial]) {

This compares the address of the objects, eg. if the pointers point to the same instance.

if([connection isEqual:[self connectionPartial]]) {

This compares the contents of the objects. For instance for two separate NSString instances, this will return YES as long as the string content is the same:

NSString *s1 = @"Something";
NSString *s2 = @"Something";
BOOL sameInstances = (s1 == s2);    // will be false, since they are separate objects.
BOOL sameContent = [s1 isEqual:s2]; // will be true, because they both are "Something"