GCBASIC documentation
Dim

String

Declared as:

    Dim <Name> As String

This allocates a RAM for a string (plus one extra byte internally). Fixed strings are not null-terminated and do not resize automatically.

Fixed-length string

Declared as:

    Dim <Name> As String [* <Length>]
    Dim <Name> * <Length>

This allocates a 16-byte string (plus one extra byte internally). Fixed strings are not null-terminated and do not resize automatically.

Element 0 and the "extra byte"

The "extra byte" mentioned above is element 0 of the string’s own memory: it holds the string’s current length, in characters. Character data itself starts at element 1, so a string declared As String * 10 reserves 11 bytes in total — 1 length byte plus 10 usable characters. This is why Len can return a string’s length instantly, without scanning for a terminator: there is no null terminator in GCBASIC strings at all, only this leading length byte. Copying, reading, and comparing strings all rely on this same convention internally.

Constraint: assigning a literal string longer than a fixed-length string’s declared <Length> compiles without warning, even though the literal’s length is already known at compile time. For example, Dim s As String * 4 followed by s = "ThisIsWayTooLong" raises no error or warning; the assignment will not fit in the allocated buffer at runtime. Keep fixed-length strings comfortably larger than the longest value you plan to assign to them.

String Escape Sequences

String literals in GCBASIC source support escape sequences, allowing arbitrary byte values to be embedded directly in strings without workarounds. This capability removes the need to use CHR() which is expensive in terms of RAM. From build 1603.

Supported Sequences

Rules

Example

    tmpstring = "\223C\\"

Produces a 3-byte string: Chr(223), C, \ — stored in the string table as:

    StringTable2:
    .DB  3, 223, 67, 92