Delphi Data Types for API Integration

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Sometime we may need to integrate APIs written on other languages into our Delphi application or we may need to call windows APIs when dealing with complex data structures or we may need to communicate with ActiveX OLE components. Then  in such cases, main issue is Data Type mismatch. So for better compatibility Delphi provides following Pointer data types which can be used to send and receive data to and from other application to Delphi applications.

Integer Data Types

Type
Description
Pointer
Byte
8-bit unsigned integer
PByte
ShortInt
8-bit signed integer
PShortInt
Word
16-bit unsigned integer
PWord
SmallInt
16-bit signed integer
PSmallInt
Cardinal
32-bit unsigned integer
PCardinal
LongWord
32-bit unsigned integer
64-bit unsigned integer
PLongWord
FixedUInt
32-bit unsigned integer
PFixedUInt
Integer
32-bit signed integer
PInteger
LongInt
32-bit signed integer
64-bit signed integer
PLongint
FixedInt
32-bit signed integer
PFixedInt
UInt64
64-bit unsigned integer
PUInt64
Int64
64-bit signed integer
PInt64
NativeUInt
64-bit or 32-bit platform-dependent unsigned integer
PNativeUInt
NativeInt
64-bit or 32-bit platform-dependent signed integer
PNativeInt



Floating-point Data Types
Type
Description
Pointer
Single
Single precision floating-point value (4 bytes)
PSingle
Double
Double precision floating-point value (8 bytes)
PDouble
Extended
Extended precision floating-point value
PExtended

String and Character Data Types
Type
Description
Pointer
AnsiChar
ANSI character
PAnsiChar
Char
Wide character (16-bit)
PChar
WideChar
16-bit character
PWideChar
AnsiString
Represents a dynamically allocated ANSI string whose maximum length is limited only by available memory.
PAnsiString
RawByteString
Use as a "codepage-agnostic" parameter to a method or function, or as a variable type to store BLOB data.
PRawByteString
UnicodeString
Unicode string
PUnicodeString
String
Alias for UnicodeString
PString
ShortString
A string of maximum 255 characters
PShortString
WideString
A string of 16-bit characters
PWideString

Boolean Data Types
Type
Description
Pointer
Boolean
Represents a logical value (true or false).
PBoolean
ByteBool
Represents an 8-bit logical value.
WordBool
Represents a 16-bit logical value.
PWordBool
LongBool
Represents a 32-bit logical value.
PLongBool

Other Data Types
Type
Description
Pointer
Variant
Represents values that can change type at run time.
PVariant
Pointer
Represents a pointer to data of any type.
PPointer
Currency
A fixed-point data type used to hold monetary values.
PCurrency


Comments

  1. MsgClubSeptember 26, 2019 at 1:45 AM

    Delphi Programming/Data types. In Delphi, like in C, VB and unlike PHP, Python or other modern languages, a variable is typed and can only contain values of this type. To make it simple, a type is a variable attribute.
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