What is the structure of a C program?

A C programme usually consists of a number of parts that are arranged in a particular structure. Here is a summary of the typical C programme structure:

1. Preprocessor Directives: These instructions are processed by the preprocessor prior to the compilation of the programme and begin with the symbol "#". They are used to declare constants, include header files, and carry out additional preprocessing operations.

2. Header Files: Using preprocessor directives, these files are added and contain declarations and definitions required by the programme. They offer constant definitions, function prototypes, and data type definitions. For input/output operations and memory allocation, header files with the extensions '' and '' are frequently used.

3. Global Declarations: This section outlines the global constants and variables that can be used across the entire programme. Global variables have a global scope and are declared outside of any function.

4. Function Declarations: This part contains the prototypes or declarations of the various functions. The functions utilised in the programme, their return types, and the kinds of parameters they accept are all disclosed to the compiler. The compiler can check the proper usage of functions before they are defined thanks to function prototypes.

5. Main Function: The main function, which acts as the program's entry point, is a need for all C programmes. It is the starting point for execution and the call-back point for other functions. An integer value is often returned by the main function as a measure of the program's execution state.

6. Function Definitions: The actual code for user-defined functions, including the main function, is contained in this section. The function body is surrounded in curly braces after the function header, which includes the function name, return type, and list of parameters in parentheses. Functions are called from the main function or from other functions, and they carry out specialised responsibilities.

7. Statements and Expressions: Statements and expressions are tools used within functions to carry out tasks, reach conclusions, manage loops, and manipulate data. Assignments, function calls, and control flow statements (if, for, while, etc.) are examples of statements that can be executed. Combinations of operators, constants, variables, and functions are called expressions, and they result in a value.



8. Comments: Comments are used to add details to the code or temporarily deactivate specific sections. They are not compiled, and the compiler disregards them. The C language supports both single-line ("//") and multi-line ("/*" and "*/") comments.

Although this is a generic framework, it's crucial to keep in mind that C programmes might differ in complexity, functionality, and coding style.