Develop Reference

Java 2D Seating Array for a Theater

import java.util.*;
/**
* Write a description of class TheaterApp here.
*
* #author (your name)
* #version (a version number or a date)
*/
public class TheaterApp {
static int [][] seats = {
{10,10,10,10,10,10,10,10},
{10,10,10,10,10,10,10,10},
{10,10,20,20,20,20,10,10},
{20,20,30,30,30,30,20,20},
{30,30,40,40,40,40,30,30},
{30,40,40,50,50,40,40,40}};
/**
* Constructor for objects of class TheaterApp
*/
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
String ans;
do {
System.out.print("Enter request, please (or 'help' or 'quit') ");
ans = input.next();
if (ans.equals("help")) {
System.out.println("Possible commands");
System.out.println("price <price>");
System.out.println("seat <row> <seat>");
System.out.println("left");
System.out.println("remaining <price>");
System.out.println("print");
System.out.println("quit");
System.out.println("help");
} else if (ans.equals("price")) {
int p = input.nextInt();
for (int i = 0; i < seats.length; i++) {
for (int j = 0; j < seats[i].length; j++) {
if (seats[i][j] == 0) {
System.out.println("Next available seat at position: " + i + " " + j);
}
}
}
// Find the 'best' seat at the given price
} else if (ans.equals("seat")) {
int r = input.nextInt();
int c = input.nextInt();
int k;
int i;
int j;
for (int l = 0; l < 6; l++) {
k = 1;
for(i=0;i<6;i++) {
for(j=0;j<8;j++) {
if (k == input.nextInt()) {
// check if the seat has already been reserved
if (seats[i][j]== 0) {
System.out.println("That seat has already been reserved");
}
// if its not reserved then reserve it
else {
seats[i][j]= 0;
}
}
k++;
System.out.println(seats[i][j]);
}
}
}
// Reserve the given row and seat, if possible
} else if (ans.equals("left")) {
// Print the total available seats
} else if (ans.equals("remaining")) {
int p = input.nextInt();
// Print the total available seats at this price
} else if (ans.equals("print")) {
for (int r = 0; r < seats.length; ++r) {
for (int s = 0; s < seats[r].length; ++s) {
System.out.print(seats[r][s] + " ");
}
System.out.println();
}
} else if (!ans.equals("quit")) {
System.out.println("Come again?");
}
} while (!ans.equals("quit"));
System.out.println("Good bye");
}
}
This array represents theater seats and I have to mark sold seats by changing the price to 0. I also have to make sure seats are open when a user asks for a a certain spot, and when a user enters a price, find any seats that are open.
So I'm pretty sure I figured out the code for finding the best seat at any given price. I can't figure out how to do the remaining code.
I just need to find out how to print the total available seats and also how to print the total available seats when a certain price is entered.
Thanks.

You'd just use nested for loops, like you did before, except now you'd have some kind of a availableSeats counter you'll increment every time a seat meets a certain condition.
Like so:
int availableSeats = 0;
for(i=0;i<6;i++) {
for(j=0;j<8;j++) {
if(seats[i][j] == sometargetprice){
availableSeats++;
}
}
}
System.out.println("Total of " + availableSeats + " are available.");
Unless I'm not understanding the problem correctly.

Java: Exception Help Char and Int

Ok all, I'm stuck again with this code.
I need to put in an Exception that won't allow the user to input 0 (because you can't divide later by 0) and the user cannot enter alpha characters. I am trying to display the message, disregard the wrong input, and loop to allow the user to try again until they put in the acceptable number.
Here is what I have:
package exceptionhandler;
/**
*
* #author Sarah
*/
import java.util.Scanner;
public class ExceptionHandler {
/**
* #param args
* the command line arguments10 10
*/
public static void main(String[] args) throws NumberFormatException {
Scanner in = new Scanner(System.in);
Scanner input = new Scanner(System.in);
System.out.print("Please enter ten values:");
System.out.println();
// Input the data into array from the user.
double[ ] digit = new double[11];
int sum = 0;
//Declare an array
try
{
for (int i = 1; i < digit.length; i++) {
System.out.print("Value " + i + ": ");
digit[i] = (double)in.nextInt();
sum += (int)digit[i];
}
catch (NumberFormatException e)
{
System.out.println("You Can Only Enter Numbers!");
}
}
System.out.println("Total Values in Array:"+ sum);
// Calculate the sum and print the total
System.out.println();
System.out.println("Would you like to divide the values?");
System.out.println("Yes or No to Exit the Program");
String a = input.next();
if(a.equalsIgnoreCase("yes")){
double [] divisionResult = new double[digit.length / 2];
//Division array declared
for (int i = 1; i < digit.length; i += 2)
{
double result = digit[i];
if (result > digit[i + 1])
result = result / digit[i + 1];
else {
result = digit[i + 1] / result;
}
divisionResult [i / 2] = result;
System.out.println(result);
}
}
else if(a.equalsIgnoreCase("no")){
System.exit(0);
}
}
}
I have tried declaring the throw exception and then tried a try..catch. But it is not recognizing catch and try talking to one another... so I know I am doing something wrong, but I can't see where it should go.
Is the Exception in the right place? Should I have done something else? Is my exception written wrong? How can I then move on to prevent the input of zero as well- rethrow?
Help?

It supposed to be InputMismatchException not NumberFormatException to catch an exception upon entering characters and you need to check for 0 if the user input 0 and deduct 1 the current index of the for-loop to let the user try again.
sample:
for (int i = 1; i < digit.length; i++) {
try {
System.out.print("Value " + i + ": ");
digit[i] = (double) in.nextInt();
sum += (int) digit[i];
if(digit[i] == 0.0)
{
System.out.println("You cant enter 0: try again");
--i;
}
} catch (InputMismatchException e) {
System.out.println("You Can Only Enter Numbers!");
--i;
in.nextLine(); //to consume the character
}
}
result:
Please enter ten values:
Value 1: 0
You cant enter 0: try again
Value 1: asd
You Can Only Enter Numbers!
Value 1:

How to exit interior loop and go back to main loop in java?

When I run this code, which is a menu with many different options. it consists of many loops. Some of which I have yet to make. But my issue arises when I have the user select "t" or the coin toss simulator. The loop begins but once the user enters the amount of coin flips say 4, it says 2.0 heads and 2.0 tails means 50.0% were heads
Type code letter for your choice: COIN TOSS SIMULATOR
Enter 0 to quit. How many tosses?
It shouldn't say type the letter for your choice: COIN TOSS SIMULATOR, enter 0 to quit. how many tosses?
Also when I enter 0 it says You have entered an invalid option. 't' is not a valid option. I want to Bring back the main menu!!!! what is going on????
public class toolBox {
public static void main(String[] args) {
Scanner myScanner = new Scanner(System.in);
boolean properInput = false;
int usersInput;
while (!properInput) {
System.out.println("Enter seed value:");
if (myScanner.hasNextInt()) {
usersInput = myScanner.nextInt();
properInput = true;
Random randomSeed = new Random(usersInput);
String randomNumberList = "";
for (int i = 0; i < 10; i++) {
randomNumberList += randomSeed.nextInt(80) + " ";
}
} else
{
String helloWorld = myScanner.next();
System.out.println("You have not entered an integer. '" + helloWorld + "' is not an integer");
}
}
outer:
System.out.println("===== CS302 TOOL BOX =====\nT > COIN TOSS SIMULATOR\nG > GRADE ESTIMATOR\nC > COLOR CHALLENGE\nQ > QUIT");
{
Scanner anotherScanner = new Scanner(System.in);
boolean usersSelection = false;
String c;
outer:
while (!usersSelection) {
{
System.out.print("" + "Type code letter for your choice: ");
}
if (anotherScanner.hasNext("q|Q")) {
c = anotherScanner.next();
usersSelection = true;
System.out.println("" + "" + "Good-Bye");
break;
}
if (anotherScanner.hasNext("t|T")) {
{
System.out.println("" + "COIN TOSS SIMULATOR" + "");
}
System.out.println("Enter 0 to quit. How many tosses?");
Random rand = new Random();
boolean headsOrTails;
float headsCount = 0;
float tailsCount = 0;
Scanner scanMan = new Scanner(System.in);
int numero = scanMan.nextInt();
if (numero == 0) {
break outer;
}
for (int j = 0; j < numero; j++) {
headsOrTails = rand.nextBoolean();
if (headsOrTails == true) {
headsCount++;
} else {
tailsCount++;
}
}
System.out.println(headsCount + " heads and " + tailsCount + " tails means "
+ (headsCount / (headsCount + tailsCount) * 100 + "% were heads"));
}
}
if (anotherScanner.hasNext("g|G")) // if the user were to enter either case of g, the
// program will register both and initialize the
// grade estimator.
{
c = anotherScanner.next();
usersSelection = true;
}
if (anotherScanner.hasNext("c|C"))
{
c = anotherScanner.next();
usersSelection = true;
System.out.println("Welcome to the Color Challenge!");
}
else {
String zoom = anotherScanner.next();
System.out.println("You have entered an invalid option. '" + zoom + "' is not a valid option.");
}
}
}
}

Your question is not clear, but your title suggests to me you think there is an inner and outer loop.
You don't have an inner and an outer loop.
Your indentation was really messy, but when I cleaned it up and then deleted a lot of extra lines of code, the structure of the code became clear.
Notice the following:
1) You have two loops, one on top switched on !properInput, the lower one switched on !usersSelection. There is also a for loop, but it doesn't do anything related to the code flow you are asking about.
2) You have two identical labels, one outside an anonymous block of code (see my comment in the code below), and another inside the anonymous block. In this case it doesn't affect your question, but it is definitely a problem.
My guess is that your break outer line isn't working because you are breaking out of the lower while loop.
I suggest you try fragmenting your code into functions to make the structure clearer.
while (!properInput) {
}
outer:
System.out.println("===== CS302 TOOL BOX =====\nT > COIN TOSS SIMULATOR\nG > GRADE ESTIMATOR\nC > COLOR CHALLENGE\nQ > QUIT");
{ /* begin anonymous code block */
outer:
while (!usersSelection) {
if (anotherScanner.hasNext("q|Q")) {
System.out.println("" + "" + "Good-Bye");
break;
}
if (anotherScanner.hasNext("t|T")) {
System.out.println("Enter 0 to quit. How many tosses?");
if (numero == 0) {
break outer;
}
for (int j = 0; j < numero; j++) {
}
}
}
}

How to make hollow box using two for loops

Use nested for loops statements to draw hallow boxes of "*"s. The boxes have the same number of rows and columns and this number should be input from the user (valid range: 5 to 21). I'm having trouble coming up with a way to make the box hollow. this is what i have for the code and it comes as a complete square, but i need it to be hollow or just the border.
System.out.println("How many rows/columns(5-21)?");
rows=input.nextInt();
while(rows<5||rows>21){
System.out.println("Out of range. Reenter: ");
rows=input.nextInt();
}
for(m=1;m<=rows;m++){
for(c=1;c<=rows;c++){
System.out.print("*");
}
System.out.println();
}
the output should look like this:
How many rows/columns (5-21)? 25
Out of range. Reenter: 7
*******
* *
* *
* *
* *
* *
*******

You need to print only some of the *s, so add a test before the print("*"). One option would be to explicitly test the four conditions (top, bottom, left, right) and OR them together logically:
if( (m==1) || //top
(m==rows) || //bottom
(c==1) || //left
(c==rows) //right
) {
System.out.print("*");
} else {
System.out.print(" ");
}
Each m== test or c== test identifies one piece of the square. Since the four tests
are ORed together, the if() is true (and a * is printed) if any one of the four tests is true. If none of them are true, the else runs and prints a space.
I also recommend renaming m to rowIndex and c to colIndex or something. When you come back to the code a week or two later, more descriptive names will make it easier to pick up where you left off. (Ask me how I know!)

import java.util.Scanner;
public class icibos {
public static void main(String[] args) {
Scanner gir = new Scanner(System.in);
System.out.print("Karenin kenarını girin: ");
int kenar = gir.nextInt();
for (int i = 1; i <= kenar; i++) {
for (int j = 1; j <= kenar; j++) {
if (i == 1 || i == kenar || j == 1 || j == kenar)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}

for (int i=1;i<=lgh;i++){
for (int a=1;a<=lgh;a++){
if(i>1 && i<lgh && a>1 && a<lgh)
System.out.print(" ");
else
System.out.print("*");
}
System.out.println("");
}

Try this , its bit hard code.
Working Example here
String myStars="*******";
String oneStar="*";
int count=0;
System.out.println(myStars);
count++;
while(count<=7)
{
System.out.println(oneStar+" "+oneStar);
count++;
}
System.out.print(myStars);

You can try this
Example is Here
String pattern;
int noOfTimes;
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the pattern to print : ");
pattern = scanner.nextLine();
System.out.print("Enter number of times it should get printed : ");
noOfTimes = scanner.nextInt();
for(int i=1; i<=noOfTimes; i++) {
System.out.println();
if(i==1 || i==noOfTimes) {
for(int j=1; j<=noOfTimes; j++){
System.out.print(pattern+" ");
}
}
else {
for(int k=1; k<=noOfTimes;k++) {
if(k==1 || k == noOfTimes) {
System.out.print(pattern + " ");
}
else {
System.out.print(" ");
}
}
}
}

import java.util.Scanner;
public class holsqr{
public static void main(String args[]){
Scanner ma=new Scanner(System.in);
System.out.print("Enter the number:");
int max=ma.nextInt();
for(int i=1;i<=max;i++){
for(int j=1;j<=max;j++){
if((i==1)||(i==max)){
System.out.print("#");
}else{
if(j==1||j==max){
System.out.print("#");
}
else{
System.out.print(" ");
}
}
}
System.out.println();
}
}
}

It pretty simple, using two while loop:
public static void main(String[] args) {
int size = 0;
int r = 0;
String star = "*";
String space = " ";
System.out.print("Input size of side of square: ");
Scanner input = new Scanner(System.in);
size = input.nextInt();
while (r < size) {
int c = 0;
while (c < size) {
System.out.print(r > 0 && r < size - 1 && c > 0 && c < size - 1 ? space : star);
++c;
}
System.out.println();
++r;
}
}

How do you stop a loop from running in Java

How do you stop a conditional loop from running. For example if I write an if statement that accepts values from 0 to 100. How do stop the program if a user enters a number less then 0 or above 100.
import java.util.Scanner;
public class TestScores {
public static void main(String[]args) {
int numTests = 0;
double[] grade = new double[numTests];
double totGrades = 0;
double average;
Scanner keyboard = new Scanner(System.in);
System.out.print("How many tests do you have? ");
numTests = keyboard.nextInt();
grade = new double[(int) numTests];
for (int index = 0; index < grade.length; index++) {
System.out.print("Enter grade for Test " + (index + 1) + ": ");
grade[index] = keyboard.nextDouble();
if (grade[index] < 0 || grade[index]> 100) {
try {
throw new InvalidTestScore();
}
catch (InvalidTestScore e) {
e.printStackTrace();
}
}
}
for (int index = 0; index < grade.length; index++) {
totGrades += grade[index];
}
average = totGrades/grade.length;
System.out.print("The average is: " + average);
}
}

You use the
break;
keyword. This breaks out of a loop.

You may want to use break
for(int i=0; i<100; i++)
{
if(user entered invalid value)
break; // breaks out of the for loop
}

Here's a hint, since this looks like homework to me: you can either use the break keyword, or use this condition:
if (grade[index] < 0 || grade[index]> 100)
{
// invalid grade...
}
as part of the loop condition.