The Class Concept

• A class is a collection of objects (or values) and a corresponding set of methods. 
• A class encapsulates the data representation and makes data access possible at a higher level of abstraction.

Example 1: A set of vehicles with operations for starting, stopping, driving, get km/liter, etc.

Example 2: A time interval, start time, end time, duration, overlapping intervals, etc.

Example 3: A string, upper case, compare, lower case, etc.

•  str.equals(otherStr) – class/Java style 
•  strcmp(str, otherStr) – C style