Decision Structures (1/30)

• Flow of Control

  • Sequence

  • Branching/Selection

• Boolean Expressions

  • Relational operators

  • Logical operators

• Decision Structures

  • if

  • if-else

System.out.println("\n Course Grade: " + grade);
if (grade >= 60)
	System.out.println("You have passed the course!");
else
	System.out.println("You have failed the course.");

• Arrangement of identifiers, literals, and operators (relational and logical) that, when evaluated, results in either true or false.

  • AND

    • &&

  • OR

    • ||

  • NOT

    • !

• Java evaluates a logical expression from left to right, stopping as soon as the final truth value can be determined.

c = 3;
d =5; 
e = 7; 
f = 9;

c < = d || e == f
true || e == f
true

/**
 * Hayley Pappas
 * 
 * RomanNumerals_V1.java
 * 
 * Given a number (1-10), determine & display the corresponding Roman Numeral
 * 
 * Input: A number (1-10)
 * 
 * Processing: 1) Prompt user for a number (1-10)
 * 			   2) Determine corresponding Roman Numeral
 * 			   3) Display result
 * 
 * Output: Corresponding Roman Numeral
 * 
 * Note: Uses one way branching - if form
 */

// Import classes
import java.util.Scanner;

public class RomanNumerals_V1 {
	public static void main(String[] args) {
		// Variables
		int number;
		String romanNumeral = "";
		
		
		// Scanner object for standard input
		Scanner stdIn = new Scanner(System.in);
		
		
		// Intro
		System.out.println("\nRoman Numeral Converter ...");
		
		
		// Prompt user for a number (1-10)
		System.out.print("\nEnter a number (1-10): ");
		number = stdIn.nextInt();
		
		
		// Determine corresponding Roman Numeral
		if (number == 1)
			romanNumeral = "I";
		if (number == 2)
			romanNumeral = "II";
		if (number == 3)
			romanNumeral = "III";
		if (number == 4)
			romanNumeral = "IV";
		if (number == 5)
			romanNumeral = "V";
		if (number == 6)
			romanNumeral = "VI";
		if (number == 7)
			romanNumeral = "VII";
		if (number == 8)
			romanNumeral = "VIII";
		if (number == 9)
			romanNumeral = "IX";
		if (number == 10)
			romanNumeral = "X";
		if (number < 1 || number > 10)    // Input validation
			romanNumeral = "";
		
		
		// Display result
		if (romanNumeral == "")
			System.out.println("Error ... Invalid Number");
		if (romanNumeral != "")
			System.out.println("The corresponding Roman Numeral is " + romanNumeral);
		
	}

}