1. Programming 2
Decision-Making

2. Planning Decision-Making Logic
Pseudocode & flowcharts are very important when it comes to the planning of decision-making logic
Don’t just sit down and start coding!
Even if it seems simple, begin the practice of designing before coding

3. The ‘if’ Structure { System.out.println(“Perfect”)’ }
Int quizScore =9;
//if the following statement is TRUE, do the
//stuff in curly braces
If (quizScore ==10) {
System.out.println(“Perfect”)’ }

4. Comparison Operators Equal to (==) Not equal to (!=) Less than (<)
Greater than (>)
Less than or equal to (<=)
Greater than or equal to (>=)
The ‘answer’ is always going to be true or false

5. Equal To / Not Equal To
If (quizScore ==10) { //do stuff } TRUE if quizScore is equal to 10 FALSE if quizScore is anything but 10 If (quizScore !=10) TRUE if quizScore is anything but 10 FALSE if quizScore is equal to 10

6. Greater Than / Less Than
If (quizScore >10) { //do stuff } TRUE if quizScore is 11 or above FALSE if quizScore is 10 or less If (quizScore <10) TRUE if quizScore is 9 or less FALSE if quizScore is 10 or greater

7. No semi—colon at end of ‘if’
Int quizScore = 9; If (quizScore == 10); { system.out.println(“Perfect”); }

8. Greater Than or Equal to Less Than or Equal to
If (quizScore >= 10) { //do stuff } TRUE if quizScore is 10 or above FALSE if quizScore is 9 or less If (quizScore <= 10) TRUE if quizScore is 10 or less FALSE if quizScore is 11 or greater

9. Make sure Not to Use Assignment Operator Instead of Equivalency
Int quizScore = 9; If (quizScore ==10) //correct! { System.out.println (“Perfect”); } ********************************** If (quizScore = 10) //Not Correct!

10. The ‘if/else’ Structure
Int quizScore = 9; //if the statement below is TRUE, do the stuff in curlys If (quizScore ==10) //correct! { System.out.println (“Perfect”); } //if the ‘if’ above is FALSE, do THIS stuff in curlys else System.out.println (“ Not Perfect”);

11. Multiple statements in ‘if/else’

12. Variable Scope public Class CompareNumbers {
Any variable declared inside a block is local to that block
The System.out.println below will not work
public Class CompareNumbers {
publicstatic void main (String [] args)
int a =1;
int b = 2;
if (a==b)
sum = a + b; }
System.out.println(sum);
A Block is lines of code between curly braces;
To correct the problem, declare the variable sum outside of the block
See next slide

13. public Class CompareNumbers{
publicstatic void main (String [] args)
int a =1;
int b = 2;
int sum;
if (a==b)
sum = a + b; }
System.out.println(sum);
Sum will print in this example because the variable was declared outside of the block

14. Constants Constant variables are variables whose values CANNOT change
public class CalcInterest {
public static void main (String[] args)
final double RATE = .008;
double savingsTotal =
double interestEarned = RATE * savingsTotal;
System.out.println(interestEarned);
RATE = .007; // can’t do this; cannot reassign }

15. Nested If/Else Statements

17. Logical AND & OR operators
OR (||) – piping symbol Shift of \
Public class CalcSales {
public static void main (String[] args)
Double salesAmount = 2500
Int bonus;
If( (salesAmount > 1000) && (salesAmount < 5000) )
bonus = 400; }

18. OR Operators
Public class CalcSales { public static void main (String[] args) Double salesAmount = 2500 Int hoursWorked = 3200 Int bonus; If( (salesAmount > 5000) || (hoursWorked > 3000) ) bonus = 400; }

19. Combining AND and OR Public class CalcSales {
public static void main (String[] args)
Double salesAmount = 2500;
Int hoursWorked = 3200;
int yearsOfService = 20;
Int bonus;
If(( (salesAmount > 5000) || (hoursWorked > 3000) ) && (yearsOfService >=20 ))
bonus = 400; }

20. Switch Statements

21. Switch Statements - continued

22. Boolean Values
Public class CalcSales { public static void main (String[] args) boolean isMale = true; if (isMale) // do stuff } else // do other stuff

23. Boolean Values
Public class CalcSales { public static void main (String[] args) boolean wonGame = false; Int myScore = 11; if (myScore >10) wonGame = true; } if (wonGame) System.out.println(“Congrats!”);

24. Code to get user input

25. Code to get user input Import java.swing.JOptionPane;
Public class HelloNameDialog {
Public static void main (String[] args)
String result;
Result = JOptionPane.showInputDialog(null, “What is your name?”);
JOptionPane.ShowMessageDialog(null, “hello, “ + result + “!”); }

26. Code to convert input from string to integer