C language : Variable

                                Variable in c language

Definition of variable-
C variable is named location in a memory where a program can manipulate the data. This location is used to hold the value of the variable.
The value of a c variable may get changed in the program. C variable might be belonging to any of the data type like int ,char, float or string etc.

Declaration of variable- 
Declaration of variable can be done in C by using following syntax:

data_type variable_name;
Or
data_type variable1,va variab2,...,variable n;

Where data_type is any valid c data type and variable_name is any valid identifier.
For eg.  int a,b,c;
               float a,b;

Variable declaration tells the compiler only two things-
1. Name of the variable.
2 . The type of data that variable will hold.

Initialization of variables- 
In C programming language variable can be initialized in the declaration statement of any block (either it may main's block or any other function block).
While declaring a variable we can provide a value to the variable with assignment operator.

Syntax of the initialization of the variable:

data_type variable_name=value;
For eg. int a=10;
              float=5.80
              char='m';
               int at[5]={1,2,3,4,5};

Scopes of variables-
Scope refers to the visibility of variables or we can say that scope is a region of a program. Variable scope is a region in a program where a variable is declared and used. So we can have three types of scopes depending on the region where these are declared and used-
1. Local variable-local variable are defined inside a function or a block.
2. Global variable-Global variable are defined outside all the functions.
3. Formal parameters- formal parameters are defined in function parameter.