WebOct 4, 2011 · The const directive on a parameter indicates that the procedure/function will not modify the value supplied in that parameter. If the procedure or function wishes to manipulate any const parameter it will first have to copy that value to a local variable.. This allows the compiler to perform some optimisations on such parameters, particularly in … WebJun 23, 2024 · 3. One way to do what you want is to change the parameter to an open array of TTest, i.e. procedure DoTest (const stest: array of TTest); But supposed you don't want to change the parameter, and really want it to be a TArray, then you can simply use the array pseudo-constructor syntax to call it (in almost all versions of Delphi, except ...
delphi - Pass different record types as parameter in a procedure ...
WebJan 23, 2013 · When you pass a variable by value, Delphi makes a copy of the parameter value in the Stack and all the changes made to that parameter inside the method are done over that copy. That's the way pascal worked since Turbo Pascal days and maybe since the beginning. Consider this: WebOct 18, 2016 · If you want to pass in an object instance instead of a class type, you can wrap GetClassElementNames () like this: function GetObjectElementNames (Object: TObject): TStringList; begin Result := GetClassElementNames (Object.ClassType); end; With that said, it is not a good idea to return a new TStringList object. thistle feeder birds
Delphi event handling, how to create own event - Stack Overflow
WebMay 6, 2011 · The compiler will get Delphi to make a copy of the string and then pass the copy, if the string parameter is declared as a CONST, right? The reason for the question is a bit tedious; we have a legacy Delphi 5utility whose days are truly numbered (the replacement is under development). WebJul 6, 2011 · I want to pass a nil value in a parameter which is declarated as procedure of object Consider this code Case 1 type TFooProc = procedure(Foo1, Foo2 : Integer) of object; procedure DoSomething Stack Overflow ... (a, b); end; procedure DoSomething(Param1:Integer);overload; begin DoSomething(Param1,nil);//here the … WebMay 22, 2014 · A var parameter cannot be optional, it must be passed a variable. For what you are looking for, use pointers instead: procedure StringProcess (StartString: string; S1:PString; S2:Pstring; S3:Pstring); begin ... if S1 <> nil then begin // Use S1^ as needed... end; ... end; Then you can do things like this: thistle feeder amazon