Abstract Classes – The Java Certification Roadmap

Abstract Methods and Classes

By Raul Rios

Abstract classes are usually meant to share pieces of implementation and to be extended:


  public abstract class Employee {
     protected String position;
     protected int experience;
     private String name;     

     // non-abstract methods (same implementation for all descendant classes)
     public String getName() {
       return name;
     }

     // abstract methods (to be implemented -differently- by descendant classes)
     abstract void getSalary();
  }

public abstract class Employee {

protected String position;

protected int experience;

private String name;

// non-abstract methods (same implementation for all descendant classes)

public String getName() {

return name;

}

// abstract methods (to be implemented -differently- by descendant classes)

abstract void getSalary();

}

Abstract methods are methods declared without an implementation (no body and semicolon at the end).


  abstract void getSalary();

abstract void getSalary();

An important thing to remember about abstract methods is that if a class has one or more abstract methods then ..Continue Reading