When to Use Inheritance ?

Inheritance is a good choice when:

• Your inheritance hierarchy represents an "is-a" relationship and not a "has-a" relationship.
• You can reuse code from the base classes.
• You need to apply the same class and methods to different data types.
• The class hierarchy is reasonably shallow, and other developers are not likely to add many more levels.
• You want to make global changes to derived classes by changing a base class.

• Composition – Composition is used when the two class has-a relationship among classes
  Inheritance – Inheritance is used when the derived class is-a relationship base class
  
  
  For example :
  Take two class
  1.House owner
  2.House
  
  
  House owner is a House is not valid - Inheritance
  House owner has a house is valid - Composition
  
  
  For example :
  Take two class
  1.Game
  2.Cricket
  
  
  
  
  Cricket is a game is valid - Inheritance
  Cricket has a game is invalid - Composition