- First we must know that the diff bet static and non static methods
is differ from static and non static variables :
- this code explain static method - non static method and what is the diff
public class MyClass {
static {
System.out.println("this is static routine ... ");
}
public static void foo(){
System.out.println("this is static method ");
}
public void blabla(){
System.out.println("this is non static method ");
}
public static void main(String[] args) {
/* ***************************************************************************
* 1- in static method you can implement the method inside its class like : *
* you don't have to make an object of this class to implement this method *
* MyClass.foo(); // this is correct *
* MyClass.blabla(); // this is not correct because any non static *
* method you must make an object from the class to access it like this : *
* MyClass m = new MyClass(); *
* m.blabla(); *
* ***************************************************************************/
// access static method without make an object
MyClass.foo();
MyClass m = new MyClass();
// access non static method via make object
m.blabla();
/*
access static method make a warning but the code run ok
because you don't have to make an object from MyClass
you can easily call it MyClass.foo();
*/
m.foo();
}
}
/* output of the code */
/*
this is static routine ...
this is static method
this is non static method
this is static method
*/
- this code explain static method - non static Variables and what is the diff
public class Myclass2 {
// you can declare static variable here :
// or you can write int callCount = 0;
// make the same thing
//static int callCount = 0; = int callCount = 0;
static int callCount = 0;
public void method() {
/*********************************************************************
Can i declare a static variable inside static member function in Java?
- no you can't
static int callCount = 0; // error
***********************************************************************/
/* static variable */
callCount++;
System.out.println("Calls in method (1) : " + callCount);
}
public void method2() {
int callCount2 = 0 ;
/* non static variable */
callCount2++;
System.out.println("Calls in method (2) : " + callCount2);
}
public static void main(String[] args) {
Myclass2 m = new Myclass2();
/* method (1) calls */
m.method();
m.method();
m.method();
/* method (2) calls */
m.method2();
m.method2();
m.method2();
}
}
// output
// Calls in method (1) : 1
// Calls in method (1) : 2
// Calls in method (1) : 3
// Calls in method (2) : 1
// Calls in method (2) : 1
// Calls in method (2) : 1