Java Basic Principles

Difference between Static and non-static method in Java

In case of non-static method memory is allocated multiple time whenever method is calling. But memory for static method is allocated only once at the time of class loading. Method of a class can be declared in two different ways

• Non-static methods
• Static methods

Difference between non-static and static Method

	Non-Static method	Static method
1	These method never be preceded by static keyword Example: void fun1() { ...... ...... }	These method always preceded by static keyword Example: static void fun2() { ...... ...... }
2	Memory is allocated multiple time whenever method is calling.	Memory is allocated only once at the time of class loading.
3	It is specific to an object so that these are also known as instance method.	These are common to every object so that it is also known as member method or class method.
4	These methods always access with object reference Syntax: Objref.methodname();	These property always access with class reference Syntax: className.methodname();
5	If any method wants to be execute multiple time that can be declare as non static.	If any method wants to be execute only once in the program that can be declare as static .

Note: In some cases static methods not only can access with class reference but also can access with object reference.

Example of Static and non-Static Method

Example

class A
{
void fun1()
{
System.out.println("Hello I am Non-Static");
}
static void fun2()
{
System.out.println("Hello I am Static");
}
}
class Person
{
public static void main(String args[])
{
A  oa=new  A();
   oa.fun1(); // non static method 
   A.fun2();  // static method
}
}

Output

Hello I am Non-Static
Hello I am Static

Following table represent how the static and non-static properties are accessed in the different static or non-static method of same class or other class.

Program to accessing static and non-static properties.

Example

class A
{
int y;
void f2()
{
System.out.println("Hello f2()");
}
}
class B
{
int z;
void f3()
{
System.out.println("Hello f3()");
A a1=new A();
a1.f2();
}
}
class Sdemo
{
static int x;
static void f1()
{
System.out.println("Hello f1()");
}
public static void main(String[] args)
{
x=10;
System.out.println("x="+x);
f1();
System.out.println("Hello main");
B b1=new B();
b1.f3();
}
}