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;

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.

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.

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>

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.

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.

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