xcode - How to let lldb print the description written in an Objective-C category -

an incredible tip debugging constraint issues print constraint`s id in lldb

but should let lldb print category`s description?

@interface nslayoutconstraint (description)  @end  @implementation nslayoutconstraint (description)  -(nsstring *)description {     return [nsstring stringwithformat:@"id: %@, constant: %f", self.identifier, self.constant]; }  @end 

help appreciated :)

you can use description method in 2 ways. one, if in code in app somewhere do:

nslog(@"my object: %@", my_object); 

then %@ specifier print nsstring returned "description" method of object.

another way in debugger:

lldb (and gdb before it) has command called po - short print-object. it's job take expression, evaluate it, interpret result (in case of objc) nsobject , send object description method.

so in debugger can call

(lldb) po object 

and printout.

one detail, though: po first checks if object responds debugdescription , call in preference description. if extending object implements debugdescription (some kit objects this) po show result of debugdescription method, not description.