1. Branching
Chapter 5
11/14/16 & 11/15/16 1 1

2. Chapter Contents Flow of Control The if Statement Basic Comparisons
Compound Statements
Basic Comparisons
Comparing Primitives
Comparing Objects 2 2

3. Chapter Contents The if-else Statement Logical Operators 3 3
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 3 3

4. Flow of Control Statements normally executed in sequence
From first to last
This sequence can be altered
A statement may call another method
Decision statements cause different sequences to be followed
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 4 4

5. Flow of Control Figure 7-1 Invoking a method 5 5
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 5 5

6. If Statement int broncos = 24; int lobos = 31; if(broncos < lobos)
System.out.println("Broncos lose!");
System.out.println("Good Night!"); 6 6

7. The if Statement Specify a condition Syntax
If condition is true one or more statements execute
If condition is false these statements skipped
Syntax
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 7 7

8. The if Statement
Figure 7-2 The logic of an if statement 8 8

9. Basic Comparisons
Figure 7-3 Relational operators that compare primitive values
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 9 9

10. Write a Program
Write a program to ask the user for her age. Output “Old Enough to Join the Army” if she is 18 or older. Next output a message that says “Army Strong.”. 10 10

11. Participation
Write a class called Thermometer. Give the class a parameterized constructor that initializes the temperature. If the value passed to the constructor is greater that 135, output “Record High!” and set the temperature to the passed value, otherwise just the temperature to the value with no output. No need to write any more methods.
Write a tester to test the constructor. 11 11

12. Compound Statements
When if statement requires multiple statements to execute
Enclose those multiple statements within braces { } after if (condition)
if(resp == YES){
System.out.println("Evaluate Launch Conditions.");
System.out.println("Respond as prompted");
System.out.println("call "); }
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 12 12

13. Comparing Objects Methods equals for String Thus, == operator
Object variable does not contain object
Object variable contains reference to it
Thus, == operator
Compares references
Not values
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 13 13

14. Comparing Objects String friend = "Sam"; //String with same data
String name = new String("Sam");
if(friend != name) //Compares addresses
System.out.println("Not the same object!");
if(friend.equals(name))
System.out.println
("Words in objects are equal."); 14 14

15. Comparing Objects
Distinct references to strings whose values are the same 15 15

16. Comparing Objects
Two variables containing equal references to the same string 16 16

17. If-else & Logical Operators
11/30/15 & 12/01/15

18. A Program with else
A program that asks the user whether the user wants a quote by Turing or another quote.
For Turing output:"Machines take me by surprise with great frequency.- Turing"
For other output:"Intelligence is the ability to adapt to change.-Hawking"
BrainyQuotes.java 18 18

19. import java.util.Scanner;
public class BrainyQuotes {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Would you like a Turing quote?");
String ans = scan.next();
if(ans.equals("yes"))
System.out.println("Machines take me" +
" by surprise with great frequency.--Turing");
else
System.out.println("Intelligence is" +
" the ability to adapt to change.--Hawking");
scan.close(); }

20. The if-else Statement
When you wish to do one thing if the condition is true
But you want to do something else when the condition is false
Syntax
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 20 20

21. The if-else Statement The logic of an if-else statement 21 21
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 21 21

22. Write an if-else Statement
Write an if-else statement that assigns 0.1 to commission unless sales is greater that or equal to , in which case it assigns 0.2 to commission.

23. Logical Operators 23 23

24. Logical Operators Logical operators
Used to combine boolean expressions
Extra parenthesis are optional.
20 <= age < 30 doesn't work
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 24 24

25. Logical Operators The operator && 25 25
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 25 25

26. Logical Operators The operator || 26 26
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 26 26

27. Logical Operators The operator !
! true -> false !("Joe".equals("Joe"))
! false -> true !("Sam".equals("Joe"))
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 27 27

28. Leap Year A year is a leap year if it is
Divisible by 4 but not divisible by 100
Or divisible by 400
Write a program to input the year. It should output a message about whether it is a leap year.

29. Precedence for Ops Order of operations in a logical expression 29 29
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 29 29

30. Wrap Up Question
How do you best compare two Strings to see if they are equal?
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 30 30

31. Participation
Write a program to input the measures of three sides of a triangle. Output a statement the says it is either “equilateral” or “not equilateral” after comparing the sides.
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 31 31

32. Branching
Chapter 5
Imagine! Java: Programming Concepts in Context by Frank M. Carrano, (c) Pearson Education - Prentice Hall, 2010 32 32