3. What is Is-a and Has-a relationship in Java code example

Example 1: has a relationship in java

‘Has a ‘ relationship is also known as “composition or Aggregation”. 
As in inheritance we have ‘extends’ keyword we don’t have any keyword to 
implement ‘Has a’ relationship in java. The main advantage of ‘Has-A‘ 
relationship in java code reusability. For has a relationship we use new keyword

Ex: Car has an engine. We cannot say Car in an engine.

Example 2: is a and has a relationship in java

class Room {

    Table table = new Table();

}