FAQs

Ques:     Types of storage class in C?
Ans:       In C there are 4 types of storage classes present
              1) Auto
              2) Extern
              3) Static
              4) Register
Auto: Auto variable are local variables define inside and function.
          Any variable can be explain in this way; Scope, Lifetime, Visibility
         ex:  int get ()
                 {
                     int age; // automatic variable
                  }
            Scope: within get method
            Lifetime: Till get method is getting executed
            Visibility : Only to get method

Ques: What is difference between static variable and volatile variable?
Ans:  static Variable:
                                 Static variable is available to the module it is defined and till compilation Unit(                                   Same source file or module).
                                or
                               Static variable is the one that exists for the life time of compilation unit (Source                                   file of module)
         Volatile Variable:
                                Volatile keyword is the hint to compiler that the variable's value might change                                     without the compiler's knowledge, therefore the compiler code optimizer can not                                   make assumptions about the variable's current value and must always re-read                                      the variable content. 
                              volatile is generally used when dealing with external events, like interrupts of                                           hardware related pins. 
                             Note: Volatile is not a type of storage, it can be stored anywhere in the memory,                                                volatile is just a type, So, by declaring variable as volatile.. it gives guarantee                                            that you will get the latest value, which may be altered by an external event.
                               
      Under construction..............