1. Catie Welsh February 14, 2011 1

2.  Program 2 Due Tonight by 11:59pm  Program 3 Assigned 2

3. 3

4. int oddSum = 0; int evenSum = 0; for (int i = 1; i <= 6; i++) { if (i % 2 == 0) { evenSum = evenSum + i; } else { oddSum = oddSum + i; } 4

5. int oddSum = 0; int evenSum = 0; for (int i = 1; i <= 6; i++) { if (i % 2 == 0) evenSum = evenSum + i;} else { oddSum = oddSum + i; } 5

6. int oddSum = 0; int evenSum = 0; for (int i = 1; i <= 6; i++) { if (i % 2 == 0) evenSum = evenSum + i; } else { oddSum = oddSum + i; } 6

7.  Indentation ◦ Makes code easier to read ◦ Helps with finding syntax and logic errors ◦ Indent code that goes between { and }  Be consistent! 7

8.  Brackets are required when your if/else or loop contains > 1 line of code!  Brackets are highly recommended when your if/else or loop contains 1 line of code  Please use brackets around all your if/else or loop statements from now on! 8

9.  Variables declared in outer scopes are visible to code inside inner scopes public static void main(String[] args) { int total = 15; int n = 5; if (n <= 10) { total = total + n; } System.out.println(total); } outer inner 9

10.  Variables declared in inner scopes are NOT visible to outer code public static void main(String[] args) { int n = 5; if (n <= 10) { int total = 15 + n; } System.out.println(total); // ERROR!!! } outer inner 10

11. if (inputString.equals(“”)) canvas.setColor(Color.BLACK); else if (inputString.equals(“BLUE”)) canvas.setColor(Color.BLUE); else if (inputString.equals(“GREEN”)) canvas.setColor(Color.GREEN); else if (inputString.equals(“RED”)) canvas.setColor(Color.RED); else canvas.setColor(Color.WHITE); 11

12. if (inputString.equals(“MOUTH”)) { mouthStartAngle = 0; } else { } 12 Also not needed when you are setting a variable to the same value it already has: ( mouthStartAngle = 180; )

13. if (inputString.equals(“MOUTH”)) { mouthStartAngle = 0; } if (inputString.equals(“EYES”)) { eyeColor = JOptionPane.showInputDialog(“Enter an eye color.”); } 13 Compiler tests both statements even if 1 st one is true

14. if (inputString.equals(“MOUTH”)) { mouthStartAngle = 0; } else if (inputString.equals(“EYES”)) { eyeColor = JOptionPane.showInputDialog(“Enter an eye color.”); } 14 Compiler only tests else if statement if the 1 st if statement is false

15. if (inputString.equals(“NOSE”)) { String input = JOptionPane.showInputDialog(“Enter an integer.”); int inputInt = Integer.parseInt(input); if(inputInt > 1 && inputInt < 4) { noseDiameter = inputInt * 10; noseDiameter = inputInt * noseDiameter; } } 15 // noseDiameter = inputInt * 10;

16.  Practice String Parsing  Practice loops - code on web (Loops.java)  Worksheet ◦ hand in for class participation ◦ Answers posted on website tonight 16

17.  Recitation  Lab 4 17

18.  Read Section 5.1  Classes ◦ You will need them to complete Program 3 18