DIFFERENT KIND OF VARIABLE OF A CLASS C#

DIFFERENT KIND OF VARIABLE OF A CLASS

kind of variable consist in a class

            You should know about variable before its kind so.

            “Variable is a name of memory storage which we used to store a value.”

Whenever we a have a value of any nature then we need a memory space from where we can store our value thus the concept of variable come into play at this time we declare a storage space to store that value the memory location are called as variable.

            We can differ its kind according its size and behavior according to this in c# we have four main kind of variable that are.

1.     Non-static variable

2.    Static variable

3.    Constant variable

4.    Read-Only variable

STATIC VARIABLE

            There are two possibilities to a variable to be a static.

Case 1

            If a variable is explicitly declare using the keyword/modifier static then that variable will and must be a static variable like this.

            static int x;         // here this x is a static variable because its define using static

                                         Keyword.

Case 2

            The second case for a variable to be static is if any variable define under a static class or static block then also that variable is known as static variable. Such as suppose Test () is a static method then,

            public static void Test ( )

            {

              int x;    // here the variable x also static because of the static block.

            }

-       The static variable can be call without instantiating its instance or object in any class of the project. We can just directly call them in any class, because it’s initializing just after deceleration implicitly by default values just after the program execute, but yes you can change it explicitly.

-       In the life cycle of a class the static variable initialize only one time. And allocate memory location immediately just after a class execute.

            -       Static variable in another word it have a fixed value so when we need not to create                               instance/object to initialized the variable thus we can change this value during creating                         instance.          

NON STATIC VARIABLE

            All the variable that declare without using a static modifier and the variable must not declare under a static class or block are known as non-static variable. Non-static variable is also known as instance. Under normal class and block we declare a variable without any modifier will also non-static such as.

            int x;

            public void Test ( )

           {

  Int x;      // non-static variable due to non-static block

            }

-       Non-static variable can call in any class by creating its instance in that class. Whenever we create instance the variable initialize by default value it is changeable.

-       Non-static variable initialize zero time if no instance are created and ‘n’ time if n instances are created. Every time of creating instance a copy of memory location is allocated for the variable in memory.

-       Non-static variable can be initialized through the constructor during instantiating object. Because its associated with creating instance.

CONSTANT VARIABLE

            “If any variable is declared by using keyword ‘const’ we call that variable as constant variable.”            

            const  datatype name = initailzed;

-       It’s understood by the name that it’s a constant variable thus we cannot modified/change once after its declaration.  Thus the value must be defined during declaration of this type of variable. Such as

            const float pi= 3.14f;  // for the float data type its mandatory to use f as suffix in c#

-       In life cycle constant variable initialize one time so it has only one memory like static variable,

-       Like static it also no require of instance creating to accessing and initializing.

-       The difference between static and constant variable is only one that this static variable can be modified and constant variable cannot be modified.\

READ-ONLY VARIABLE

            “The variable that is declared using readonly keyword is called as readonly variable.”  This variable cannot modify after initialized.

            readonly  datatype <name>;

-       For the readonly variable it is not require initializing during declaration. But once it’s declared it cannot be change. It can initialize under a constructor of class.

Like suppose Test ( ) is a class then,

            readonly  bool flag;

public void class ( )

{

 this.flag = false;

            }

-       The behavior is similar to non-static so it can have ‘n’ copies of the readonly variables, because it initialized after creating the instance n time of creating instance a copy of this variable have.    

-       The readonly variable can initialize in the constructor of class or during creating instance, not after this not first.