What character is used to denote the end of a string in C?

In C programming, the end of a string is denoted by a null character, represented as \0. This character serves a crucial function in string handling within the language. When a string is defined in C, it is stored as an array of characters, and the null character indicates to functions that operate on strings where the string terminates. This is essential for functions such as printf, strlen, and others that rely on the null terminator to determine the length of the string and process it accordingly.

The null character is distinct and plays a vital role in how strings are handled in memory. Without this character marking the end, functions may continue reading memory beyond the intended string, potentially leading to undefined behavior or errors.

In contrast, other options do not serve this purpose. A space is just a regular character within a string and does not indicate termination. A backslash on its own does not have any significance related to string termination; while it is used as an escape character in C, it does not denote the end of a string. An asterisk is commonly used in various contexts in C, such as pointers, but it does not relate directly to string termination.