[jmassung]

After reading the OOP and the Obj-C Language book from ADC I have a question regarding messages vs. function calls: what is the reaction time?

A function executes NOW. In C++, if I do:

myObject->myFunctionCall();

it executes before anything after it does. However, from all my past coding experience, a message is sent (via FIFO) to an object and is handled when the object "gets to it". So:

[myObject myFunctionCall];

could execute much later than its C++ counterpart. Is this true in Objective-C? or am I missing a piece of the puzzle?

Thanks,
Jeff

[lindberg]

There's no FIFO queue, or anything like that.

With every ObjC call, the message name is used to do a lookup on the receiver's class to find the corresponding implementation (a C function really), and then calls that function. This is called "dynamic binding", where the function to be called is determined at runtime instead of at compile time ("static binding").

The use of dynamic binding does actually open up a world of new possibilities, but in the typical case your method just gets called as normal.