StringObject.md

String Object

CStrObject is the VM's built-in string type. Not an XAP node, but registered as a script-accessible object so XAP scripts can call methods on string values.

Script Methods

Method	Signature	Description
length	() -> int	Returns the string length
charCodeAt	(index) -> int	Returns the character code at the given index
charAt	(index) -> string	Returns a single-character string at the given index
concat	(str) -> string	Returns a new string with str appended
indexOf	(substr [, start]) -> number	Returns the first index of substr, or -1
lastIndexOf	(substr [, start]) -> number	Returns the last index of substr, or -1
substr	(start [, length]) -> string	Returns a substring starting at start for length chars
substring	(start, end) -> string	Returns chars between start and end indices
toLowerCase	() -> string	Returns a lowercased copy (uses _tcslwr on Xbox)
toUpperCase	() -> string	Returns an uppercased copy (uses _tcsupr on Xbox)

Immutability

The string type is effectively immutable for script purposes. All methods that produce modified text return new CStrObject instances rather than mutating the original. This matches the ECMAScript string semantics that the XAP scripting language borrows from.

Implementation Notes

_tcslwr and _tcsupr are the Xbox CRT's locale-aware case conversion functions (TCHAR variants). These operate in-place on the internal buffer of the newly-created return string, not on the caller's string.