Päisefailide

Päisefailide, often translated as "header files" in English, are a fundamental concept in programming, particularly in compiled languages like C and C++. They serve as declarations or prototypes for code that is defined elsewhere, typically in a separate source file. The primary purpose of a header file is to provide information about functions, variables, data structures, and macros that are available for use by other parts of a program.

When a programmer includes a header file in their source code, they are essentially telling the compiler where to find the necessary declarations for elements defined in that header. This allows the compiler to check for correct usage of these elements, such as function signatures and variable types, during the compilation process. The actual implementation, or the code that performs the actions described by the declarations, resides in a corresponding source file (often with a .c or .cpp extension).

Header files help in modularizing code, making it more organized and easier to manage. They promote code reusability by allowing multiple source files to access the same set of declarations without needing to redefine them repeatedly. This separation of declaration from definition is crucial for the compilation process, enabling the linker to later combine the compiled object files into a final executable program. Common examples include standard library headers like <stdio.h> for input/output operations or <iostream> for C++ stream manipulation.