What is the structure of a C program?

A basic structure of a C program typically consists of: 1. **Preprocessor Directives:** These are lines of code that begin with a `#` symbol. They are instructions to the compiler to include certain files or libraries before compiling the program. 2. **Main Function:** Every C program must have a `main()` function. It serves as the entry point of the program where execution begins and ends. Inside the `main()` function, you write the instructions for the program to perform. 3. **Variable Declarations:** Before using any variables, you declare them. This involves specifying the data type and name of the variable. Variables hold data that can be manipulated within the program. 4. **Executable Statements:** These are the actual instructions or statements that perform the desired tasks. They can include assignments, calculations, conditionals (if-else), loops (for, while), function calls, etc. 5. **Return Statement (optional):** The `main()` function typically ends with a `return` statement, which returns an integer value to the operating system indicating the success or failure of the program. The absence of a `return` statement implicitly returns 0, indicating successful execution. Here's a simple example: ```c #include int main() { // Variable declaration int num1, num2, sum; // Executable statements printf("Enter two numbers: "); scanf("%d %d", &num1, &num2); sum = num1 + num2; printf("Sum: %d\n", sum); // Return statement return 0; } ``` This program prompts the user to enter two numbers, calculates their sum, and then prints the result. Finally, it returns 0 to indicate successful execution. read less