Delphi in a Nutshell

Name

Integer Type

Syntax

type Integer = -2147483648..2147483647;

Description

The Integer type is the basic integer type. The size of an integer can vary with different versions of Delphi. Currently, Integer is a 32-bit type, but future versions might change the size.

Delphi defines a number of integer types of varying ranges. The predefined integer types are shown in the following table.

Type	Minimum	Maximum
Byte	0	255
ShortInt	-128	127
Word	0	65,535
SmallInt	-32,768	32,767
LongWord	0	4,294,967,295
LongInt	-2,147,483,648	2,147,483,647
Integer	natural	natural
Cardinal	0	natural
Int64	-9,223,372,036,854,775,808	9,223,372,036,854,775,807

Tips and Tricks

• Numeric constants are type Integer if they fall within the range of Integer; otherwise, they are of type Int64. Arithmetic expressions with at least one argument of type Int64 yield a result of type Int64. If both arguments are integer types, the result type is Integer.

• The size of the Cardinal and Integer types can change from one release of Delphi to another. In Delphi 5, both are 32 bits, but a future version of Delphi will undoubtedly change the size to 64 bits.

• Whenever possible, you should use an explicit subrange. If you know that a value will always be positive, for example, declare the variable accordingly. The additional type safety helps catch mistakes (where you accidentally assign a nonpositive number to the variable), and it helps to document the program by giving the reader additional information ...