CS 303E Class 13 do Loops and Nested Loops

1
CS 303E Class 13do Loops and Nested Loops
Let's play two! - Ernie Banks When you open your
mind to unlimited potential, you can accomplish
anything. -Ernie Banks
2
do-while Loop

• Syntax
• do
• //body of loop
• First_Statement
• ...
• Last_Statement
• while(Boolean_Expression)
• Initialization code may precede loop body

3
do-while Loop

• Loop test is after loop body so the body must
  execute at least once (minimum of at least one
  iteration)
• May be either count controlled or event
  controlled loop
• Good choice for event controlled loop
• Something in body of loop should eventually cause
  Boolean_Expression to be false
• Another tool, but stick to while and for loops

4
Nested Loops

• Any kind of code may be contained in a loop
• including another loop
• Tracing of code and variables is very important
  in understanding the behavior of nested loops
• What is the output of the following code?
• for(int limit 1 limit lt 10 limit limit
  1)
• for(int num 0 num lt limit num num 1)
• System.out.print( (num 2 1) " ")
• System.out.println()

5
Using Nested Loops

• Write a program that find all the prime numbers
  between 2 and N.

6
More on Nested Loops

• Write a program to create a chessboard pattern on
  an applet.
• getWidth and getHeight methods from Applet class