Use of static modifier

[Stephen Silva]

Write an application where the static modifier becomes useful.

Can some one please, give me a good example to this assignment.


I have written a code to explain the consequences of static modifier.
But I need an application of that.
Thanks.

[Prabhjot Jassal]

assume you are writing a soccer application :-)..and your task is to keep track of all the goals scored so far at an international level...static modifier is probably the best way to keep track of it

[John Stark]

Static methods: Writing utility methods like finding the sum of two integers:

class Utilities
{
	public static int sum(int a, int b)
	{
		return a + b;
	}
}	

There is no need to create an instance of Utilities. All you want is calling the sum() method with two integers and getting the sum back.

Static variables: Counting the created instances of some class:

class Main
{
	public static int nMain = 0;

	public Main()
	{
		nMain++;
	}
}

There is only one variable nMain per class. There is no point using an instance variable. What we want is one variable counting the created instances of the class Main.

Anyone an example for static nested classes?

John

[Stephen Silva]

Thanks a lot for the answers.

But I need a simple application which shows the usage of the static modifier.
If you have any sample codes, but simple ones can you help me in this regard.

Thanks.

[Anjali Vaidya]

Let us take an example when you want to use methods of another class but its constructor is private so that you cannot create an object. In that case, make the specific method which you want to use anyhow, as static

public class StaticDemo
{
    int a=100;
    int b=200;

	public static void main(String[] args)
	{

		StaticDemo con=new StaticDemo(); //works because main is in the same class
		System.out.println("a="+con.a); 
		System.out.println("b="+con.b);
		
                A obj=new A(); //works only if A constructor is not private, so here comment this to make program work
		System.out.println("x="+A.x);  //obj.x, if x is not static
	        A.abc(); //obj.abc();   if abc() is not static
	}
}

class A
{
	private static int x;
	private A()
	{
		x=5;
	}
	public static void abc()
	{
		A obj1=new A();
		System.out.println("In method abc, x="+obj1.x);
	}

}

So basically, you can use static if you want to access any method or variables without creating object of the class.
You can also use static block
static()
{
...
}

static blocks are executed before main(). So you can write statements here too. For example: giving some instructions to the user before he enters some value

[Stephen Silva]

Thanks a lot for the reply