C Foundation

What is C? C Compiler Installation C Extensions C Compiler C Interpreter C Program Structure

C Basics

C Keywords C Data Types C Identifiers C Variables C Constant C Escape Sequences C Constant and Volatile C Typecast


What is Operator C Comma Operator C Arithmetic Operators C Relational Operators C Logical Operators C Bitwise Operators C Conditional Operators C : : Operator C Operator Priority

Basic IO's

Basic IO's C Formatted Functions C Unformatted Functions C Common Functions

Control Statements

What is Control Statement C if Statement C if else Statement C Nested if Statement C Else if Statement C Break Statement C Continue Statement C Switch Statement C Goto Statement


What is Control Loop C for Loop C Nested for Loop C while Loop C Nested while Loop C do while Loop C Nested do while loop


What is Function C User Defined Functions C Recursion C Passing Parameters


Scope C Local Scope C Global Scope

Storage Classes

What is Storage Class C Auto C Extern C Static C Register


What is Array C One Dimensional Array C Two Dimensional Array C Multi Dimensional Array C Arrays Of Strings


What is String C String Functions


What is Pointer C Pointers Arithmetic C Pointer to Pointer C Pointers and Arrays C Pointers and Strings C Pointer to Functions Void Pointers Null Pointers C Null and Void Pointer


What is Structure C Struct within Struct C Array within Structure C Pointer to Structure C Structure and Function C Enum C Bitfield Structure C Type def


What is Union


What is File C read a file C write a file C File Handling C Error Handling C Low Level Disk I/O C Other file functions

Memory Allocation

What is Memory Allocation C Malloc() C Calloc() C Free() C Realloc() C Coreleft()

C Reference

All ASCII Code Basic C Questions

C Interview

C Interview Sets All Star Patterns All Number Patterns All Alphabet Patterns All Series Patterns
The ones who are crazy enough to think they can change the world are the ones who do.
- Steve Jobs

C Storage Classes Interview Questions

36. Define storage classes and what are the different types of storage classes in C?

A storage class defines the scope, visibility and life-time of variables. Refer For More C Storage Classes

  • auto storage class
  • static storage class
  • register storage class
  • extern storage class

37. Define auto storage class?

  • All variables declared inside a function without any storage classes keyword is considered as auto storage class by default.
  • In auto storage class a memory is allocated automatically to the variables when the function is called and deallocates automatically when the function exits.
  • Variables under auto storage classes are local to the block or function. So, it is also called as local variables.
  • The keyword auto is rarely used because all uninitialized variables are said to have auto storage classes.

Refer For More C Auto Storage Classes

38. Define static storage class?

  • A static variable is a variable that tells the compiler to retain the value until the program terminates.
  • They are created once when the function is called, even though the function gets repeated it retains the same value and exists until the program terminates.
  • The default value of static variable is zero(0).
  • The keyword for a variable to declared under static storage class is static

Refer For More C Static Storage Classes

39. Define register storage class?

  • Register variables are similar to auto variables. The only difference is register variables are stored in CPU register instead of memory.
  • Register variables are faster than normal variables. Mostly programmers uses register to store frequently used variables.
  • Programmers can store only few variables in the CPU register because size of register is less.
  • The keyword for a variable to declared under register storage class is register.

Refer For More C Register Storage Classes

40. Define extern storage class?

  • extern variable is a programmer's shorthand to represent external variable.
  • extern variables are also known as global variables because extern variables are declared above the main function.
  • So, the variables can be accessed by any function.
  • We can also access extern variables of one file to another file. But make sure both files are in same folder. The keyword for a variable to declared under extern storage class is extern.

Refer For More C Extern Storage Classes

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