A Varaible is declared as int x and another varaible is declared as st

Question

A Varaible is declared as int x and another varaible is declared as static x ? what will be the difference between them?

Sachin Singh · Answer

Never go for book definition of anything , always stick with usage of thing. So the question is when do you need to declare a variable as static?   okk, There is college where you study , you create a class college and declare a lot of variables inside it, now wait and think about the college name , do you really need to change college name per object, no, it should be same throught in the application. so whenver you find anything that should take memory once and there is no chance of change that with each object then declare that as static. ex:- public static  string collegeName ="DAV"; similarly consider Pi (3.14) class  circle    {        static  float _PI = 3.14 F;       public int Radius;          public funtionArea(int radius)       {           return this.radius * Circle._PI             }   }   class program   {       public  static  void main()       {           Circle c 1  = new Cirle();           float area 1  = c 1 .functionRaduis( 5 );           Circle c 2  = new Cirle();           float area 2  = c 1 .functionRaduis( 6 );       }   }
Now no matter how many instances are made for the class circle , only one copy exists of variable _PI saving our memory.

Rajanikant Hawaldar · Answer

Hello Nihaan, A static variable is shared by all instances of the class, while an instance variable is unique to each instance of the class. A static variable's memory is allocated at compile time, they are loaded at load time and initialized at class initialization time. In the case of an instance variable all of the above is done at run time. An instance variable is one per object: every object has its own copy of its instance variable. public   class  Test{          int  x = 5;       }      Test t1 =  new  Test();      Test t2 =  new  Test();   Both t1 and t2 will have their own copy of x. A static variable is one per class: every object of that class shares the same static variable. public   class  Test{          public   static   int  x = 5;       }      Test t1 =  new  Test();      Test t2 =  new  Test();   Both t1 and t2 will share the same x.

Farhan Ahmed · Answer

int is a datatype for a variable storing integer values. static int is a variable storing integer values which is declared static.
If we declare a variable as static, it exists till the end of the program once initialized. For example, if we declare an int variable in a function, then that variable is a local variable for that function which gets destroyed as the function ends. But if we declare an int variable in a function also as static, then that variable will not get destroyed as the function ends and will not get destroyed until the program ends.