Chapter 6 Exercises

Chapter 6 Exercises

1.  while:    A loop structure, which executes a set of statements over and over again based on a condition.
    do-while: In the do-while statement the condition is not evaluated until after the first execution of the loop.


2.
package review.prompter;
import java.util.Scanner;
public class ReviewPrompter {
    public static void main(String[] args) {

        int min, max, num;

        Scanner input = new Scanner(System.in);
        System.out.print("Enter the minimum number: ");
        min = input.nextInt();
        System.out.print("Enter the maximum number: ");
        max = input.nextInt();
        System.out.print("Enter a number between " + min +" and " + max +": ");
        num = input.nextInt();

        while(num >= max || num <= min){
            System.out.print("Wrong! Try again: ");
            num = input.nextInt();
        }
    }
}


3.  A Sentinel is a constant that stores a value that is used to signify that a loop should stop iterating.


4.
package review_percentpassing;
import java.util.Scanner;
public class Review_PercentPassing {
    public static void main(String[] args) {
        int score;
        int scoreValues = 0;
        int passing = 0;
        double avg;
        final int SENTINEL = 0;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a score out of 100 (Enter 0 to finish): ");
        score = input.nextInt();
        while(score != SENTINEL){
            scoreValues += 1;
            if(score >= 70){
                passing += 1;}
        System.out.print("Enter another score: ");
        score = input.nextInt();}
        input.close();
        avg=(double)passing / (double)scoreValues;
        System.out.printf("%2.2f %2s\n",avg * 100 , " Percent Passing");
    }
}


5.
package review_oddsum;
import java.util.Scanner;
public class Review_OddSum {
    public static void main(String[] args) {
        int num;
        int num2 = 1;
        int oddSum = 0;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a number: ");
        num = input.nextInt();

        while (num2 != num){
            num2 ++;
            if (num2 % 2 == 1){
                oddSum ++;
            }
        }
        System.out.print("Odd sum is : " + oddSum);
    }
}


6.
package chapter6.pkg6;
import java.util.Scanner;
public class Chapter66 {
        public static void main(String[] args) throws Exception {
            for ( int i=0; i<80; i++ ){
		if ( i%10 == 0 ){
                    System.out.print("Parkside Robotics is cool. \t");
                    Thread.sleep(200);}
            }
        }
    }


7.
package stringdemo;
import java.util.Scanner;
public class StringDemo {
    public static void main(String[] args) {
        String phrase, threeLetters;
        int phraseLength;
        int mid;
        Scanner input = new Scanner(System.in);

	System.out.print("Enter text that contains at least three characters: ");
        phrase = input.nextLine();
        input.close();

        phraseLength = phrase.length();
        mid = phraseLength / 2;

        threeLetters = phrase.substring(mid - 1, mid + 2);
        System.out.println("Middle three characters are: "
        + threeLetters);
    }
}


8.  a) The position of a character in string is called its index
    b) A string is said to be immutable because it cannot be changed
    c) A string without an assigned value
    d) Generated from calling a methof from a String object
    e) The Unicode Standard is a 16-bit encoding system that assigns a value for each character and symbol of every language


9.
package review_accountsetup;
import java.util.Scanner;
public class Review_AccountSetup {
    public static void main(String[] args) {
        String username, password;
        int passLength;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a username: ");
        username = input.nextLine();
        System.out.print("Enter a password that is at least 8 characters: ");
        password = input.nextLine();
        passLength = password.length();

        while (passLength < 8){
            System.out.print("Enter a password that is at least 8 characters: ");
            password = input.nextLine();
            passLength = password.length();}

        username = username.toLowerCase();
        password = password.toLowerCase();

        System.out.println("Your username is "+ username + " and your password is " + password);
    }
}


10.
package formalgreeting;
import java.util.Scanner;
public class FormalGreeting {
    public static void main(String[] args) {
        String name, nameL;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter your name, including your title: ");
        name = input.next();
        nameL = name.toLowerCase();

        if ("mr.".equals(nameL) || "mr".equals(nameL)){
            System.out.println("Hello, sir.");
        }else{
            if ("ms.".equals(nameL) || "ms".equals(nameL) || "mrs.".equals(nameL) || "mrs.".equals(nameL) || "miss".equals(nameL)){
            System.out.println("Hello, ma'am.");
            }else{
                System.out.println("Hello, " + name);}}
    }
}


11.
    #5   60 times

    #6 	 x = 0

    #11	 a) 10
	 b) "my "
	 c) "my string."
	 d) There would be an error that would be fixed by adding () after "toUpperCase"
	 e) "my string."

    #12  a) false
	 b) true
	 c) 24
	 d) 0
	 e) -8
	 f) 9
	 g) 9
	 h) true
	 i) true


12.
    #18 Monogram

package monogram;
import java.util.Scanner;
public class Monogram {
    public static void main(String[] args) {
        String first,  middle, last;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter yuor first name:     ");
        first = input.nextLine();
        first = first.toLowerCase();
        System.out.print("Enter your middle initial: ");
        middle = input.nextLine();
        middle = middle.toLowerCase();
        System.out.print("Enter your last name:      ");
        last = input.nextLine();
        last = last.toUpperCase();
        input.close();

        System.out.println("Your monogram is: " + first.substring(0,1) + last.substring(0,1) + middle.substring(0,1));
    }
}


    #19 RemoveString

package removestring;
import java.util.Scanner;
public class RemoveString {
    public static void main(String[] args) {
        String sentence, remove, sentence2;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a sentence: ");
        sentence = input.nextLine();
        System.out.print("Enter a string:   ");
        remove = input.nextLine();
        input.close();

        sentence2 = sentence.replace(remove + "","");
        System.out.println(sentence2);
    }
}


    #21 GroupAssignment

package groupassignment;
import java.util.Scanner;
public class GroupAssignment {
    public static void main(String[] args) {
        String first, last;
        int group1, group2;
        Scanner input = new Scanner(System.in);

        System.out.print("Enter your first name: ");
        first = input.nextLine();
        System.out.print("Enter your last name:  ");
        last = input.nextLine();
        input.close();

        group1 = last.compareToIgnoreCase("i");
        if (group1 < 1){
            System.out.println(first + " " + last + " is assigned to Group 1");}
        else{
            group2 = last.compareToIgnoreCase("s");
            if (group2 < 1){
                System.out.println(first + " " + last + " is assigned to Group 2");}
            else{
                System.out.println(first + " " + last + " is assigned to Group 3");}
        }
    }
}