1. DOCUMENTATION SECTION GLOBAL DECLARATION SECTION
Structure of C program
DOCUMENTATION SECTION
PREPROCESSOR SECTION
DEFINITION SECTION
GLOBAL DECLARATION SECTION
main() {
Declaration part;
Executable Part; }
sub program section
Body of the subprogram;

2. Documentation Section Preprocessor Section Global Declaration Section
It contains the comment lines.
Preprocessor Section
It is used to link library files.
Global Declaration Section
The Global declaration section comes at the beginning of the program and they are visible to all parts of the program.
Declaration Section
It describes the data to be used within the function.
Executable Part
It contains the valid statements.

3. C Programs C program may have many functions.
One and only one of the functions MUST BE named main.
main is the starting point for the program.
main and other functions in a program are divided into two sections, declaration section and statement section.

4. Preprocessor Directives
Special instructions to the preprocessor that tells how to prepare the program for compilation
E.g: include : tells the processor to include information from selected libraries known as header files e.g. <stdio.h>

5. Comments (Program documentation)
The compiler simply ignores comments when it translates the program into executable code.
To identify a comments, C uses opening /* and closing */ comment tokens.

6. Comments (Cont) Comments can appear anywhere in a program.
Comments are also found wherever it is necessary to explain a point about a code.
Comments cannot be nested in C i.e. you cannot have comments inside comments.

7. C program /* Example program in C*/ Comments
# include <stdio.h> Preprocessor Section
Global Declaration
void main ()
{ Local declaration
printf (“Hello World! \n”); Statements }
Output :
Hello World