Lecture 6: Controlling the flow; toString

lecture video

toString

For classes that we write, the default toString method returns the memory location of the object. If we want something more useful, we can override the method.

Use this tutorial if you need another reference.

Loops

• for
• while
• do while: see this tutorial

Branches

• if
• else if
• else
• switch: see this tutorial

Files used in class

See previous lecture for a toString example. We will also use the Project 1 starter code to look at examples of controlling the flow.

Additional exercises

• R-1.5 from book: Write a short Java method that takes an integer n and returns the sum of all positive integers less than or equal to n.
• R-1.8 from book: Write a short Java method that counts the number of vowels in a given character string.
• Write a short Java method that takes a char grade and returns it as a double GPA score. You can use the following conversions: A (4.0), A- (3.7), B+ (3.3), B (3.0), B- (2.7), C+ (2.3), C (2.0), C- (1.7), D+ (1.3), D (1.0) and F (0.0). Write this method both using a series of else if statements and using a switch statement.