Int64: is the largest integer in Delphi, with a 64-bit signed integer

declaration: Type Int64 = -9223372036854775808..9223372036854775807;

Description: Int64 is a signed integer that is 64-bit stored. This size is already fixed and will not change in future Delphi versions. Functions like IntToStr also support the Int64 type (implemented by overloading).

When an integer constant exceeds the maximum value of an integer type, it is cast to the Int64 type.

Note: There are no unsigned 64-bit integers in Delphi.

The comp type is also a 64-bit signed integer that is now not recommended for use.

{Show Int64 storage range} var   min, Max:int64; begin   //Get type maximum and minimum   min: = Low (Int64);   Max: = High (Int64);   ShowMessage (' min Int64 value = ' +inttostr (min));   

Program Run Result:

Min Int64 value = 9223372036854775808

Max Int64 value = 9223372036854775807

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Delphi 64 vs. 32-bit differences

Transferred from: Http://www.neugls.info/?p=91&lang=zh Recently, Delphi launched a 64-bit preview version, I do as a faithful delphier, see this news, the first time to learn, and write this as a reference for the future. The same point: In the Delphi 64-bit version, the unicodestring,ansistring,widestring in use with 32 no difference, only the index into 64 bits, such as: S[i] in the I became 64 bits. singed Types DELPHI/32 DELPHI/64 Shortint 1 bytes ← SmallInt 2 bytes ← Longint 4 bytes ← Integer 4 bytes ← Int64 8 bytes ← unsinged Types DELPHI/32 DELPHI/64 Byte 1 bytes ← Word 2 bytes ← Longword 4 bytes ← Cardianl 4 bytes ← UInt64 8 bytes ← ← symbol indicates the same size as Delphi/32 Different places: nativeint,nativeuint-64 bits Point (all pointers)-bits Dynamic arrays-64-bit Indexing Floating point math–double Point String Class instance Class reference Interface Ansistring Widestring UnicodeString Procedure pointer Dynamic Array Pansichar Pwidechar PChar The above type is 4 bytes in 32 bits and 8 bytes under 64 bits. Generally speaking: The same Windows API, such as: Createwindowex,peekmessage,etc the same Delphi RTL:SYSUTILS,CLASSES,GENERICS.COLLECTIONS,ETC VCL is the same: forms,graphics,controls,menus,etc error handling is also the same: try...finally ....., try....exception ... Under 64 bits, these calling conventions will be seen as consistent: Register,passcal, Cdecl,stdcall DELPHI/64 does not support Pascal with Basm (ASM), only the pure ASM procedure is supported. The preceding four-pass register of the calling procedure or function also becomes: RCX, RDX, R8, R9 (or XMM0-XMM3) A display cast is required when working with the message structure body, for example: SendMessage (Hwnd,wm_settext,0,lparam (@MyCharArray)); Message.result:=lresult (self);