Static domain and static method

Static domain

class Employee {
    
	private static int nextId = 1;
	private int id;
}

• Each employee object has its own id Domain , But all instances of this class share one nextId Domain
• namely , If there is 1000 individual Employee Class object , Then there are 1000 Instance fields Id, But there is only one static domain nextId
• Even if there is no employee object , Static domain nextId Also exist
• Static fields belong to classes , Does not belong to any independent object
• In most object-oriented programming languages , Static fields are called class fields

static const

• Very few static variables , But static constants are often used .

Static methods

• A method that cannot perform an operation on an object

Static methods don't have this Parameter method

• Static methods cannot access instance domains , But you can access static domains in your own classes

public static int getNextId(){
    
	return nextId;	//return static field
}