Weil das Thema gerade wieder aufkam (http://www.purebasic.fr/german/viewtopi ... 15#p344515) und ich vor ein paar Wochen mal manches davon zusammengetragen hatte weil ich es mir nicht immer merken konnte:
Code: Alles auswählen
EnableExplicit
Debug "----------------------------- 1:"
; protected can shadow global
Global d1
Procedure p1()
Protected d1
d1 + 1
Debug d1
EndProcedure
p1() ; 1
P1() ; 1
Debug d1 ; 0
Debug "----------------------------- 2:"
; static can shadow global
Global d2
Procedure p2()
Static d2
d2 + 1
Debug d2
EndProcedure
p2() ; 1
P2() ; 2
Debug d1 ; 0
Debug "----------------------------- 3:"
; define cannot shadow global
; Global d3
;
; Procedure p3()
; Define d3 ; error: Variable already declared with a different scope
; d3 + 1
; Debug d3
; EndProcedure
;
; Define d3 ; error: Variable already declared with a different scope
Debug "----------------------------- 4:"
; procedure-local define does not conflict with main-local define and behaves like protected
Define d4
Procedure p4()
Define d4
d4 + 1
Debug d4
EndProcedure
p4() ; 1
P4() ; 1
Debug d4 ; 0
Debug "----------------------------- 5:"
; access to globals is implizit in procedures, even with EnableExplicit
Global d5
Procedure p5()
d5 + 1
Debug d5
EndProcedure
p5() ; 1
P5() ; 2
Debug d5 ; 2
Debug "----------------------------- 6:"
; access to main-locals in procedures needs explicit Shared
Define d6
Procedure p6()
Shared d6
d6 + 1
Debug d6
EndProcedure
p6() ; 1
P6() ; 2
Debug d6 ; 2
Debug "----------------------------- 7:"
; main-locals need to be declared before procedure to be accessible
; Procedure p7()
; Shared d7 ; error: With 'EnableExplicit', variables have to be declared
; d7 + 1
; Debug d7
; EndProcedure
;
; Define d7
;
; p7()
; P7()
; Debug d7
Debug "----------------------------- 8:"
; main-globals need to be declared before procedure to be accessible
; Procedure p8()
; d8 + 1 ; error: With 'EnableExplicit', variables have to be declared
; Debug d8
; EndProcedure
;
; Global d8
;
; p8()
; P8()
; Debug d8
Debug "----------------------------- 9:"
; Global in procedure creates main-global
Procedure p9()
Global d9
d9 + 1
Debug d9
EndProcedure
Procedure p99()
Debug d9
EndProcedure
p9() ; 1
P9() ; 2
Debug d9 ; 2
p99() ; 2
Debug "----------------------------- 10:"
; Shared does not care if already global
Global d10
Procedure p10()
Shared d10 ; ok
d10 + 1
Debug d10
EndProcedure
p10() ; 1
P10() ; 2
Debug d10 ; 2
Debug "----------------------------- 11:"
; you cannot define main-globals and main-locals together inside a procedure
Global d11_global_a ; main-global
Define d11_local_a ; main-local
Procedure declareVariables()
Global d11_global_b ; main-global
Define d11_local_b ; procedure-local
;Shared d11_local_c ; error: With 'EnableExplicit', variables have to be declared
EndProcedure
Debug "----------------------------- 12:"
; Define.<type> without variable to change the default type has been removed as of pb 5.60,
; the documentation is out-of-date (pb 5.61) but it's mentioned in the history/changelog
;Define.w ; Syntax error
;Define d12
Debug "----------------------------- 13:"
; Global does not complain about redeclaration as long as the type does not change. That includes
; the case where the second declaration does not use any type and intends to use the default type
Global g13.a = 255 ; somewhere
; ...
Global g13 ; assume integer and zero-initialization?
g13 + 1
Debug g13 ; 0
Procedure p13()
Global g13
g13 + 1
Debug g13 ; 1
EndProcedure
p13()
Debug "----------------------------- 14:"
; Define does not complain about redeclaration but gives error for different implicit type
Define d14 = 100 ; somewhere
; ...
Define d14 ; assume zero-initialization?
d14 + 1
Debug d14 ; 101
Define d14b.a
;Define d14b ; error: Variable already declared with another type
Procedure p14()
Define d14 = 200
; ...
Define d14 ; assume zero-initialization?
d14 + 1
Debug d14 ; 201
Define d14_.a = 200
;Define d14_ ; error: Variable already declared with another type
EndProcedure
p14()
Debug "----------------------------- 15:"
; Protected does not allow redeclaration at all
Procedure p15()
Protected d15
;Protected d15 ; error: Local variable already declared
EndProcedure
Debug "----------------------------- 16:"
; Threaded
; threads share variables by default (one variable instance for all threads)
Global d16_global = 100 ; main-global
Define d16_local = 200 ; main-local
d16_global + 1
d16_local + 1
Debug d16_global ; 101
Debug d16_local ; 201
Procedure p16(param)
Shared d16_local
d16_global + 1
d16_local + 1
Debug "thread: " + d16_global ; 102
Debug "thread: " + d16_local ; 202
EndProcedure
Define thread = CreateThread(@p16(), 0)
WaitThread(thread)
Debug "----------------------------- 17:"
; Threaded ..is like Global, but with separate variable instances per thread
; use Threaded instead of Global for that purpose, don't try to combine Threaded/Define/Shared etc.. in a declaration
Threaded d17_threaded_a = 100 ; initialized for each thread instance
Threaded d17_threaded_b
d17_threaded_a + 3 ; affects only main thread instance
d17_threaded_b = 500 ; affects only main thread instance
d17_threaded_b + 3 ; affects only main thread instance
Debug d17_threaded_a ; 103
Debug d17_threaded_b ; 503
Procedure p17(param)
d17_threaded_a + 1
d17_threaded_b + 1
Debug "thread: " + d17_threaded_a ; 101
Debug "thread: " + d17_threaded_b ; 1
EndProcedure
Define thread = CreateThread(@p17(), 0)
WaitThread(thread)
