Lecture 4: Objects; reference vs. primitive data types; type casting

lecture video

Classes and objects

• Procedural programming vs. object oriented programming
• creating and using objects
• constructors
• fields
• methods
• running programs with main

Reference vs. primitive data types

• reference data types store the location of the data (an object)
• primitive data types store the actual data

Type casting

• explicit vs. implicit
• remember that Java is NOT dynamically typed (unlike Python)

Files used in class

• Counter.java
• CounterDemo.java
• MoreWithDataTypes.java

Additional exercises

• Exercie R-1.10 from the book: Write a Java class, Flower, that has three instance variables of type String, int, and float, which respectively represent the name of the flower, its number of petals, and price. Your class must include a constructor method that initializes each variable to an appropriate value, and your class should include methods for setting the value of each type and getting the value of each type.