#include once "fbserialize.bi"
payload = Serialize( value )
payload = Serialize( array() )

value
array()

An owned binary String containing a complete version 1 serialization payload. Success sets Err to zero. Failure returns an empty string and sets Err to FB_SERIALIZE_INVALID (1) or FB_SERIALIZE_OUT_OF_MEMORY (4), declared by fbserialize.bi. Even an empty source string produces a nonempty payload on success.

The compiler supplies traversal instructions for the source type. Public fields of ordinary UDTs, nested UDTs, fixed and dynamic arrays, and owned string contents are encoded automatically. No field registration or handwritten member codec is needed.

Supported values include Boolean, signed and unsigned integer types, enums, Single, Double, String and fixed String * N. Strings preserve embedded null bytes; fixed strings preserve every stored byte. UDT padding, pointers and runtime descriptors are not included in the payload.

Raw or procedure pointers, ByRef fields, bitfields, unions, inheritance, non-public fields, ZString, WString, UString and UDTs with user-defined constructors, destructors or operators are rejected at compilation. Compiler-generated lifetime operations for strings and arrays are supported.

The payload uses little-endian logical values and an exact structural schema. Native Integer and UInteger values use 64 wire bits, allowing compatible 32-bit and 64-bit applications to exchange values within the reader's range. See Compiler-assisted serialization for schemas, bounds, limits and versioning.

Serialize does not perform file or network I/O. Pass the binary string's Len together with its bytes to interfaces which need a byte count. The caller must synchronize access if another thread can modify the source during encoding.

'' examples/manual/udt/serialize.bas
''
'' FreeBASIC Manual: SERIALIZE
'' Purpose: Make an independent snapshot of a record with owned members.
'' Responsibilities: Nested records, strings, arrays and deep ownership.
'' This example intentionally contains no file or network transport.
'' --------

#include Once "fbserialize.bi"

Type Item
    label_text As String
    quantity As Integer
End Type

Type PlayerState
    player_name As String
    health As Integer
    inventory(Any) As Item
End Type

Dim As PlayerState original, restored
original.player_name = "Player One"
original.health = 100
ReDim original.inventory(-2 To 0)
original.inventory(-2).label_text = "Potion"
original.inventory(-2).quantity = 3

Dim As String payload = Serialize(original)
If Err <> 0 Then
    Print "Serialize failed: "; Err
    End 1
End If

If Deserialize(payload, restored) = 0 Then
    Print "Deserialize failed: "; Err
    End 1
End If

'' The restored record owns its strings and arrays. Changing the source
'' and releasing its array and the payload do not change the restored data.
original.player_name = "Changed"
original.inventory(-2).label_text = "Used"
original.inventory(-2).quantity = 0
Erase original.inventory
payload = ""

'' Check restored bounds before accessing an element of the owned array.
If LBound(restored.inventory) <> -2 OrElse UBound(restored.inventory) <> 0 Then End 1
If restored.player_name <> "Player One" OrElse restored.health <> 100 Then End 1
If restored.inventory(-2).label_text <> "Potion" Then End 1
If restored.inventory(-2).quantity <> 3 Then End 1

Print restored.player_name
Print restored.inventory(-2).label_text
Print restored.inventory(-2).quantity

'' end of serialize.bas

Output:

Player One
Potion
 3

• Available in the -lang fb and -lang fblite dialects; unavailable in -lang qb.
  
  

• New to FreeBASIC. The public name is an opt-in macro from fbserialize.bi. Without this include, an application may still use Serialize as its own identifier.
  
  

• Deserialize
  
• Compiler-assisted serialization
  
• Put (File I/O)
  
• Err