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Initialize memory block using RTTI
Source position: system.fpd line 96
procedure Initialize( |
var T: TAnyType; |
ACount: SizeInt = 1 |
); |
Initialize is a compiler intrinsic: it initializes a memory area T for any kind of managed variable. Initializing means zeroing out the memory area. In this sense it is close in functionality to Default, but Default requires an already initialized variable. It performs the opposite operation of finalize, which should be used to clean up the memory block when it is no longer needed.
The optional ACount parameter can be used to initialize an array. It then specifies the number of elements in the array.
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Finalize (clean up) memory block using RTTI |
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Return Default initialized value |
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Return pointer to type information for type |
{ This example demonstrates the use of the Initialize and Finalize functions used to initialize (and clean up) any RTTI-enabled data not allocated with New or Create. } {$mode objfpc} {$h+} // use ansistrings, they need to be initialized. Type PData = ^TData; TData = record Street,City,Zip,Country, Tel: String; StreetNumber : Integer; end; var Data: PData; begin // Do not use New. GetMem(Data,SizeOf(TData)); Try { Initialize the structure in memory, using Run-Time Type Information} Initialize(Data^); { Assign some string data to the ansistring contents. Note that this only works because the record was zeroed out by Initialize} Data^.Street:='Sesame Street'; Data^.City:='Heaven'; Data^.Zip:='7777777'; Data^.Country:='Spain'; Data^.StreetNumber:=3; Finally { Clean up the record contents. Again, the structure of the record is detected through Run-time Type Information } Finalize(Data^); FreeMem(Data); end; end.
{ This example demonstrates the use of the Initialize and Finalize functions used to initialize (and clean up) any RTTI-enabled data not allocated with New or Create. } {$mode objfpc} {$h+} // use ansistrings, they need to be initialized. Type PData = ^TData; TData = record Street,City,Zip,Country, Tel: String; StreetNumber : Integer; end; var Data: PData; begin // We use the fact that a pointer is also usable as an array. GetMem(Data,SizeOf(TData)*2); Try { Initialize the structure in memory, using Run-Time Type Information} Initialize(Data^,2); { Assign some string data to the ansistring contents. Note that this only works because the record was zeroed out by Initialize} Data[0].Street:='Sesame Street'; Data[0].City:='Heaven'; Data[0].Zip:='7777777'; Data[0].Country:='Spain'; Data[0].StreetNumber:=3; // Second, well known street Data[1].Street:='Wall Street'; Data[1].City:='New York'; Data[1].Zip:='10005'; Data[1].Country:='USA'; Data[1].StreetNumber:=11; Finally { Clean up the record contents. Again, the structure of the record is detected through Run-time Type Information } Finalize(Data^); FreeMem(Data); end; end.