static keyword

 The static keyword is mainly used in java for Memory Management.

• static can be

1. block

2. variable

3. method

4. nested class

• static is not related to any specific object, It is common to the entire class. 
• It means that " we can invoke static member without creating an object"

static method:

public static void m1(){

}

1. we can call the static method from non static method.
2. we can call the static method from another static method
3. but,  we cannot call non static method from static method. we need to create an object.

static block:

A block of code that has a static keyword

static {

System.out.println("hai");

}

• The static block will be executed before the main method(static block gets executed when the class is loaded in memory)
• static block has more priority than main method
• The class can have more than 1 static block.
• Uses: It is used to initialize a static variable

static variable:

If a variable contains the static keyword, It is called static variable.

static int first = 0;

• static variables are shared among all the objects inside the class.
• class-level variable.
• Only single copy of the static variable is created and shared.

static nested class:

the static class will be created inside another class called a static nested class

public class statickeyword {

static class statickey{

// TODO Auto-generated method stub

}