ZString
Standard data type: 8 bit character string
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.
Syntax
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
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
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
