Question about CocoaMessage, sharedApplication, delegate

[Wolfram]

If I use the same cocoaMessage multiple times inside my program will it work like a procedure or
will it compile the same code on every line where I write it?

Is it fine to store the sharedApplication and appDelegate in a global variable on program start or is there something to consider?

[wilbert]

If I use the same cocoaMessage multiple times inside my program will it work like a procedure or
will it compile the same code on every line where I write it?

CocoaMessage is a procedure just like any other builtin procedure.

Is it fine to store the sharedApplication and appDelegate in a global variable on program start or is there something to consider?

That should be fine.