zeroterminated

Zero-terminated, also known as null-terminated, refers to a method of representing strings as a sequence of characters that ends with a terminator character whose value is zero. In C and many C-family languages, strings are stored as arrays of char terminated by the null character ('\0'). The terminator marks the end of the string; the length is not stored explicitly, and the content may be scanned to determine its length.

How it works: standard string operations rely on the terminator to determine where the string ends. For example, the C standard library functions strlen, strcpy, and strcat scan memory until they encounter '\0'. The terminator is considered part of the storage but not part of the string's logical length. This representation is efficient for small, frequently modified strings but can be unsafe if a terminator is missing or corrupted, potentially causing memory access beyond the end.

Advantages and risks: Advantages include simple memory model and compatibility with C APIs, as well as cheap storage for short strings and straightforward pointer arithmetic. Risks include buffer overruns when writing without ensuring a terminator, difficulty handling binary data that may contain 0 bytes, and the need for careful bounds checks in low-level code. Some languages and data structures opt for length-prefixed or length-scoped strings instead of termination-based strings.

Variations: In wide-character strings, the terminator is the corresponding wide null character (L'\0'). In modern C++ programming, std::string stores a length explicitly and does not rely on a trailing null for most operations, though it is still null-terminated for compatibility with C APIs. In other languages, string representations are length-based or encoded with explicit size fields, making zero termination unnecessary.