{% highlight java %} /** * --------------------------------------------------------------------------- * File name: ForLoopAnswers.java * Project name: Winter Study Guide * --------------------------------------------------------------------------- * Author’s name and email: Michael Schneider, schneidm@etsu.edu * Course-Section: All * Creation Date: 1/5/15 * Last modified: Schneider 1/5/15 schneidm@etsu.edu * --------------------------------------------------------------------------- */ import java.util.Scanner; /** * Class Name: ForLoopAnswers
* Class Purpose: To give answers for the for loop exercises
* *
* Date created: 1/5/15
* Last modified: Schneider 1/5/15 schneidm@etsu.edu * @author Michael Schneider */ public class ForLoopAnswers{ public static void main(String[] args){ /******************************************************* * * Examples * ********************************************************/ //Create a for loop that displays 0 to 15 to the screen //The counter (i) is initialized to 0 // //The conditional statement (i < 16) states that the for loop will end when // the counter is no longer less than 16 (i.e. when the counter reaches 16) // //The incrementer (i++) states that the counter will only increase by values of 1 // for(int i = 0; i < 16; i++) { System.out.print(" " + i); } //Create a for loop that only displays even numbers between 0 and 30 //The counter is initialized at 0, the first number in our range // //The conditional statement (i <=30) states that the loop will end when // the counter reaches a value greater than 30 // //The incrementer (i+=2) states that the counter will increase by values of 2, // since the counter is initialized as an even number, only the even numbers // in the range will be displayed. // for(int i = 0; i <= 30; i+=2) { System.out.println(" " + i); } //Rewrite the previous for loop to use a conditional statement to check // if the counter is even. //The only change made from the previous for loop is in the incrementer. // The incrementer now only increases the counter by 1. This moves the // logic for checking if the counter is even into the for loop itself. // for(int i = 0; i <=30; i++) { //Remember mod (%), returns the remainder from a division. If a number // is divided by 2 and the remainder is 0, we have an even number. if(i %2 == 0) { System.out.println(" " + i); } } /********************************** * *Counting Exercises * ***********************************/ //Problem 1 //Create a for loop that counts from 1 to 10 for(int i = 1; i < 11; i++){ System.out.println("Counter: " + i); } //Problem 2 //Create a for loop that counts from 3 to 15 for(int i = 3; i < 16; i++){ System.out.println("Counter: " + i); } //Problem 3 //Create a for loop that counts from 0 to 50 by counting by 5 for(int i = 0; i < 51; i+=5){ System.out.println("Counter: " + i); } //Problem 4 //Create a for loop that counts from 10 to 1 for(int i = 10; i > 0; i--){ System.out.println("Counter: " + i); } //Problem 5 //Create a for loop that counts from 50 to 0 by counting down by 5 for(int i = 50; i >= 0; i-=5){ System.out.println("Counter: " + i); } //Problem 6 //Create a for loop that count by multiples of 3, up to 90 for(int i = 1; i <= 90; i*=3){ System.out.println("Counter: " + i); } /********************************** * *Repetitive Exercises * ***********************************/ //Problem 1 //Sum all the numbers from 1 to 50 int sum = 0; for(int i = 1; i <= 50; i++){ sum+= i; } System.out.println("The sum of all values from 1 to 50 is: " + sum); //Problem 2 //Display all odd numbers from 0 to 16 for(int i = 0; i <= 16; i++){ if(i%2==1){ System.out.println(i + " is odd"); } } //Problem 3 //Take 10 numbers, find their sum Scanner keyboard = new Scanner(System.in); sum = 0; for(int i = 0; i < 10; i++){ System.out.println("Please enter number " + i + " of 10 : "); sum+= keyboard.nextInt(); } System.out.println("The total is: " + sum); //Problem 4 //Take 10 numbers from the user, display a message if // x < 100 : "That number is a bit low" // 100 < x < 200 : "That number is perfect!" //x > 200 : "That number is crazy high!" for(int i = 0; i < 10; i++){ System.out.println("Please enter a number: "); int number = keyboard.nextInt(); if(number < 100){ System.out.println("That number is a bit low"); } else if(number < 200){ System.out.println("That number is perfect!"); } else{ System.out.println("That number is crazy high!"); } } //Problem 5 //Take 10 number pairs and provide a menu for the user // 1. Find the sum // 2. Find the difference // 3. Find the product // 4. Find the quotient //Process the user's choice with if/else statements for(int i = 0; i < 10; i++){ System.out.println("Please enter the first number: "); int firstNumber = keyboard.nextInt(); System.out.println("Please enter the second number: "); int secondNumber = keyboard.nextInt(); //Display menu System.out.println("------Math Menu-------"); System.out.println("1. Find the sum"); System.out.println("2. Find the difference"); System.out.println("3. Find the product"); System.out.println("4. Find the quotient"); System.out.println("Please enter your choice: "); int choice = keyboard.nextInt(); if(choice == 1){ int add = firstNumber + secondNumber; System.out.println("The sum of " + firstNumber +" + " +secondNumber + " = " + add); } else if(choice == 2){ int diff= firstNumber - secondNumber; System.out.println("The difference of "+ firstNumber +" - " +secondNumber + " = " + diff); } else if(choice == 3){ int prod = firstNumber * secondNumber; System.out.println("The product of " + firstNumber +" * " +secondNumber + " = " + prod); } else if(choice == 4){ int quot = firstNumber / secondNumber; System.out.println("The quotient of " + firstNumber +" / " +secondNumber + " = " + quot); } else{ System.out.println("You did not enter a recognized option from the menu"); } } //Problem 6: Rewrite Problem 5 using a switch statement to process the user's // response. for(int i = 0; i < 10; i++){ System.out.println("Please enter the first number: "); int firstNumber = keyboard.nextInt(); System.out.println("Please enter the second number: "); int secondNumber = keyboard.nextInt(); //Display menu System.out.println("------Math Menu-------"); System.out.println("1. Find the sum"); System.out.println("2. Find the difference"); System.out.println("3. Find the product"); System.out.println("4. Find the quotient"); System.out.println("Please enter your choice: "); int choice = keyboard.nextInt(); switch(choice){ case 1: int add = firstNumber + secondNumber; System.out.println("The sum of " + firstNumber +" + " +secondNumber + " = " + add); break; case 2: int diff= firstNumber - secondNumber; System.out.println("The difference of "+ firstNumber +" - " +secondNumber + " = " + diff); break; case 3: int prod = firstNumber * secondNumber; System.out.println("The product of " + firstNumber +" * " +secondNumber + " = " + prod); break; case 4: int quot = firstNumber / secondNumber; System.out.println("The quotient of " + firstNumber +" / " +secondNumber + " = " + quot); break; default: System.out.println("You did not enter a recognized option from the menu"); } } } } {% endhighlight %}