Program Structure

Let us look at structure of a C program

A C program consist of following parts:

Preprocessor Commands

Functions

Variables

Statements

Comments

Let us look at a simple code that would print "Hello World"

    
#include <stdio.h>
int main() {
	/* First C program */
    printf("Hello World");

	return 0;
  }

    

Now, Take a look at various parts of program...

1. First line of program #include <stdio.h> is a preprocessor command, that tells the C compiler to include stdio.h file before actual compilation.
2. Next line int main() is the main function. It is the beginning of a program execution.
3. Next line /*....*/ will be ignored by compiler. These lines are called comments.
4. The next line printf(...) is a function that prints the message.
5. The next line return 0; terminates the main function and return the value 0.