What is a Preprocessor in Computer Programming?

A preprocessor is a program that processes the source code of a computer program before it is compiled or assembled. The preprocessor performs various tasks, such as:

1. Macro expansion: It replaces macros with their definitions.
2. Include file processing: It includes other header files into the current file.
3. Conditional compilation: It enables or disables certain parts of the code based on defined conditions.
4. Tokenization: It breaks the source code into individual tokens, which are then processed by the compiler.
5. Error reporting: It reports errors and warnings found in the source code.

The preprocessor's main goal is to prepare the source code for the compiler by performing these tasks and producing a modified version of the source code that can be compiled more efficiently. The output of the preprocessor is typically a modified version of the source code, which is then fed into the compiler for further processing.