Definitions for "Extends"
Keyword indicating that a class inherits from another class.
indicates inheritance of a super- or parent class. In the following example, Brass inherits the properties of Instrument: class Instrument { public void play( Note n ) { System.out.println("Ta-daaaaaaa!"); } public String what() { return "Instrument"; } } class Brass extends Instrument { public void play( Note n ) { System.out.println(" " + n + " loud and brash"); } public String what() { return "Brass";
Class X extends class Y to add functionality, either by adding fields or methods to class Y, or by overriding methods of class Y. An interface extends another interface by adding methods. Class X is said to be a subclass of class Y. See also derived from.
A relationship from one use case to another, specifying how the behavior defined for the first use case can be inserted into the behavior defined for the second use case.