**Include Header File Section **
C program depends upon some header files for function definition that are used in program. Each program file by default is extended with ".h". The header file should be included using # include directive as given here.
Global Declaration
This section declares some variables that are used in more than one function. These variables are known as global variables. This section must be declarfed outside of all the function.
Function Main
Every program written in C language must contain main() function. The function main() is a starting point of every C program. The execution of the program always begins with the function main().
Declaration Path
The declaration path declares entire variables that are used in executable part. The initialisations of variables are also done in this section. Initialisation maens providing initial value to the variable.
Executable Path
This path contains the statements following the declaration of the variables. This part contains a set of statements or a single statements. These statements are enclosed between the braces.
Identifiers
Identifiers are the names if variables, function and arrays. They are user-defined names, consisting sequence of letters and digits, with the letter as the first character.
Variables
It is a data name used for storing a data value. Its valye may be changed during the program execution. The value of variables keeps on changing during the execution of the program.
Scope
Scope of variables tells compiler the visibility of variable in the block.
typedef
It is used to create new data type. But it is commonly used to change existing data type with another name. Syntax:
typedef [data_type] synonym;
OR
typedef [data_type] new_data_type;
Examole:
typedef int integer;
integer rno;
