ZString
 
Standard data type: 8 bit character string

Syntax

Dim variable As ZString * size
Dim variable As ZString Ptr

Description

A ZString is a C-style fixed-size array of chars. It has no descriptor so it's faster to pass it as an argument to functions. FreeBASIC avoids any overflow that could occur, by truncating the contents.

A ZString Ptr can point to a standard ZString, also can be used to implement an "user-managed" ZString, in this case Allocate/Reallocate/Deallocate must be used to size-resize-dispose it and is up to the user to avoid overflows .

The end of the string is marked by a character 0 ASCII, this is automatically managed by the FreeBASIC string handling functions. A character 0 ASCII must never enter in the text of a ZString or it will be truncated, as no descriptor exists .

In a ZString, Len returns the size of the contained string and SizeOf returns the space allocated to the ZString.

This type is provided for easy interfacing with C libraries and to also replace the fixed-length strings, that can't be managed through pointers. Any intrinsic string functions like Left will work with ZString's too, plus any string operator.

Example

Dim As ZString * 14 str1 => "hello, world"
Print str1
Print Len(str1)    'returns 12, the size of the string it contains 
Print SizeOf(str1) 'returns 14, the size of the variable


Dim As ZString Ptr str2
str2 = Allocate( 14 )
*str2 = "hello, world"
Print *str2
Print Len(*str2)      'returns 12, the size of the string it contains 
Print SizeOf(*str2)  'returns len(zstring), the size of the variable


Dialect Differences

  • Not available in the -lang qb dialect unless referenced with the alias __Zstring.

Differences from QB

  • New to FreeBASIC

See also