Java loop with same method but with different system.out [closed] - java

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I am taking an Java Introduction class and we have a project that deals with a hangman game. I have most of the all code worked out but there is a way to simplify the code.
In my code below, the program will output a message for every round (max 3 round) then using game.nextRound() it set will a word using variable named word1, word2, word3. This variable will be called in sequence in descending order.
import java.util.Scanner;
public class Game {
public static void main(String[] args) {
String word1 = "ruby";
String word2 = "python";
String word3 = "swift";
Scanner kb = new Scanner(System.in);
Hangman game = new Hangman();
System.out.println("Let's play a round of hangman.");
System.out.println("We are playing hangman");
game.nextRound(word1);
while (true) {
System.out.println("");
System.out.println("The disguised word is " + game.disguised());
System.out.println("Guess a letter:");
char guess = kb.next().charAt(0);
boolean isFound = game.guessLetter(guess);
if (isFound) {
game.result();
if (game.disguised().equals(game.secret())) {
game.found();
break;
}
} else {
game.result();
}
}
System.out.println("");
System.out.println("Let's play a second round of hangman.");
System.out.println("We are playing hangman");
game.nextRound(word2);
....
....
....
Hangman.java
public String disguised() {
return disguisedWord;
}

You can do the following :
-Put the Strings word1, word2, and word3 in an array of type String.
Let's say
String[] words = {"ruby", "python", "swift"};
-Initialize an int counter set to 0.
int c = 0;
-Add game.nextRound(words[c++]); inside your if and else statements in the while loop.

You can use ArrayList, and also use counter to indicate the number of the game.
public class Game {
public static void main(String[] args) {
int count = 1;
List<String> words = new ArrayList<>();
words.add("ruby");
words.add("python");
words.add("swift");
for (String word : words) {
System.out.println("Let's play a round of " + count + "hangman.");
System.out.println("We are playing hangman");
Hangman game = new Hangman();
game.nextRound(word);
while (true) {
System.out.println("");
System.out.println("The disguised word is " + game.disguised());
System.out.println("Guess a letter:");
char guess = kb.next().charAt(0);
boolean isFound = game.guessLetter(guess);
if (isFound) {
game.result();
if (game.disguised().equals(game.secret())) {
game.found();
break;
}
} else {
game.result();
}
}
count++;
}
}
}

Related

Java error about turning sentence into camelCase [closed]

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I'm starting to code and trying to do a challenge of turning a sentence into camelCase. After some experimenting on my own, got to the following code:
package teste;
import java.util.Scanner;
public class Teste {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.print("Insert the sentence to be turned into camelCase: ");
String entry = keyboard.nextLine();
System.out.print("Insert the character that is used as space: ");
String space = keyboard.nextLine();
char current;
char next;
String output = null;
for (int i=0; i<=entry.length(); i++){
current = entry.charAt(i);
next = entry.charAt(i+1);
if (i == entry.length()){
output += Character.toLowerCase(current);
} else if (entry.substring(i, i+1).equals(space)){
output += Character.toUpperCase(next);
i++;
} else {
output += Character.toLowerCase(current);
}
}
System.out.println("This sentence in camelCase is: " + output);
}
}
There is an error I can't seem to avoid with the last index of the input, even with the first if structure made especially for it, and I can't find out why. Could anyone explain to me what I did wrong?
you should avoid StringIndexOutOfBoundsException exception in line 15 "entry.charAt(i+1)",
This code will fix your error.
import java.util.Scanner;
public class Teste {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.print("Insert the sentence to be turned into
camelCase: ");
String entry = keyboard.nextLine();
System.out.print("Insert the character that is used as
space: ");
String space = keyboard.nextLine();
char current;
char next;
String output = "";
for (int i=0; i<entry.length()-1; i++){
current = entry.charAt(i);
next = entry.charAt(i+1);
if (i == entry.length()-2){
output += Character.toLowerCase(current);
} else if (entry.substring(i, i+1).equals(space)){
output += Character.toUpperCase(next);
i++;
} else {
output += Character.toLowerCase(current);
}
}
//here we test the last character
int len=entry.length();
current = entry.charAt(len-1);
if(!entry.substring(len-1, len).equals(space)){
output += Character.toLowerCase(current);
}
System.out.println("This sentence in camelCase is: " +
output);
}
}

Trying to print out some sequence of numbers [closed]

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I want to print out a sequence of numbers using this formula
Enter a number
if number is even divide number by 2.
But if number is odd multiply number by 3 and add 1
continue doing this until number becomes 1
sample input=3
Sample output=10 5 16 8 4 2
this is what I tried but still not getting it
package victor;
import java.util.Scanner;
public class proj {
public static void main(String[] args) {
Scanner put=new Scanner(System.in);
int temp=0;
boolean notOne=true;
System.out.println("input::: ");
int num=put.nextInt();
while(temp!=1){
if (num%2==0){
temp=num;
System.out.println(temp/2);
break ;
}
else {
temp=num;
System.out.println(temp*3+1);
break;
}
}
if(temp!=1){
notOne=false;
}
}
}
It's not working because you keep re-assigining the variable temp to the initially scanned num.
You keep checking if the initially scanned num is odd or even, when you should check if temp is odd or even.
You also break out of the loop for no reason.
And finally, you're not saving the result of the operations, you're only printing out the result.
Try to understand the points I mentioned above by noticing the differences between your code and the following:
while(temp!=1){
if (temp%2==0){
temp = temp/2;
}
else {
temp = temp*3+1;
}
System.out.println(temp);
}
You are not updating the value of temp. You are just printing it. Take the following statement
if (num%2==0){
temp=num;
System.out.println(temp/2);
break ;
}
Here you are setting temp to num and just printing temp/2 and never setting a value.
I wrote my version of it which is a bit more simpler. I hope this will help you. You can create a string to get a better output of course.
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter a number:");
int number = scan.nextInt();
while (number != 1) {
number = number % 2 == 0 ? number / 2 : ((number * 3) + 1);
System.out.println("Number became " + number);
}
}
}
Try this:
public class Main
{
public static void main(String[] args) throws Exception
{
System.out.println("Starting...");
//Lets start the program, first we need
//the Scanner class to access to the input
Scanner stdin = new Scanner(System.in);
System.out.print("Type a num: ");
//I dont use: nextInt() because when asking for another input, will scan only
//the rest of the line (Maybe just \n - line break )
int num = Integer.parseInt(stdin.nextLine());
//Optional
int loops = 0;
while(num!=1){
//Pair, so num/2
if ( num %2 == 0){
num/=2;
}
else{
//num*3 +1
num=num*3 +1;
//Note that:
//1 + num*3
//Doesnt alter the result
}
System.out.println("num: "+num);
loops++;
}
System.out.println("total loops: "+loops);
}
}

How to determine if user's input string is read the same backwards ( palindrome ) JAVA [closed]

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package com.jetbrains;
import java.util.Objects;
import java.util.Scanner;
public class SA {
public static void main(String[] args) {
//scanner object
Scanner input = new Scanner(System.in);
//comment
System.out.println("Please enter a line of text below:");
String letters = input.nextLine(); //User's string input
if (letters.length() < 7) {
System.out.println("The input is too short.");
}
//variables
int l = letters.length()-5; //where the last 5 characters are located in user's input string
String answer = letters.substring(l) + letters.substring(2,l) + letters.substring(0, 2); // first 2 & last 5 swapped
if (letters.length() > 7) {
System.out.println("Convert to upper cases:");
System.out.println(letters.toUpperCase());
System.out.println("Swap the first 2 characters with the last 5 characters:"); // Swap
System.out.println(answer);
System.out.println("Is it a palindrome?");
for (int i = (letters.length() - 1); i >= 0; i--) {
char backwards = (letters.charAt(i));
for (int n = letters.indexOf(0); n >= 0; n++) {
char forwards = (letters.charAt(n));
if (Objects.equals(forwards, backwards)) {
System.out.println("True");
else
System.out.println("False");
}
}
}
}
}
}
I've tried comparing my user's input by making the for-loop outputs into char variables but it always returns false. I'm not sure how to fix this last bit, I've tried doing other things but I am completely stumped. My class hasn't learned StringBuilder or StringBuffer so I cannot use them in my code. Any tips or hints would be very helpful, thank you.
I have modified your code little bit to get the correct result -
import java.util.Scanner;
public class StringAnalysis {
public static void main(String[] args) {
//Create scanner object
Scanner input = new Scanner(System.in);
//Comment to the user
System.out.println("Please enter a line of text below:");
String letters = input.nextLine(); //User's string input
if (letters.length() < 7) {
System.out.println("The input is too short. No analysis to be performed.");
}
//variables
int l = letters.length() - 5; //States the index number of where the last 5 characters are located in user's input string
String answer = letters.substring(l) + letters.substring(2, l) + letters.substring(0, 2); // first 2 & last 5 swapped
if (letters.length() > 7) {
System.out.println("Analysis #1: Convert to upper cases:"); // Upper case
System.out.println(letters.toUpperCase());
System.out.println("Analysis #2: Swap the first 2 characters with the last 5 characters:"); // Swapping
System.out.println(answer);
System.out.println("Analysis #3: Is it a palindrome?");
String backwards = "";
for (int i = (letters.length() - 1); i >= 0; i--) {
backwards = backwards + letters.charAt(i);
}
if(letters.equalsIgnoreCase(backwards)) {
System.out.println("True");
} else {
System.out.println("False");
}
}
}
}
You have a problem on the second loop for checking palindrome , i tried to solve it , but eventhough , it compares every backward letters to all forwards which is logically wrong , here is something better you can do :
System.out.println("Analysis #3: Is it a palindrome?");
boolean response = true;
for (int i = 0 ; i < letters.length() ; i++) {
String backwards = String.valueOf(letters.charAt(i));
String forwards = String.valueOf(letters.charAt(letters.length()-i-1));
if(!backwards.equals(forwards)) {
response = false;
}
}
System.out.println(response);

Having a hard time doing this Palindrome on Java [closed]

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I'm having a hard time learning java and I was hoping to get some type of help on doing this. I'm trying to get the user to input a word and have the system check to see if its a palindrome. I've taken some code from others to get some help but I'm getting stuck.
import java.util.Scanner;
class PalidromeTester
{
public static boolean isPalindrome (String[] word) {
for (int i=0; i< word.length; i++) {
if (!word[i].equals( word[word.length-1-i])){
return false;
}
}
return true;
// read word
public static String readWord(Scanner input){
String word = input.nextLine();
word = word.toLowerCase();
return word;
}
// display results to the screen
public static void displayResults(boolean result){
// display the results
String msg = "\nThat string ";
msg += (result == true) ? " IS " : " is NOT ";
msg += " a palindrome.\n";
System.out.println(msg);
}
// main function
public static void main(String[] args){
// input scanner
System.out.print('\u000C');
System.out.println("Enter the word: ");
Scanner input = new Scanner(System.in);
PalidromeTester.readWord(input);
}
}
Assuming your need, I think this is what you need. I have commented the changes done in the code itself to point out to you why the changes were done in the first place. Also remember there are multiple ways to approach a problem, this is merely just one of those possibilities. Feel free to innovate and add your own technique for solving this.
import java.util.Scanner;
public class Palindrome { //<-- added public to the class otherwise main method won't be called
public static boolean isPalindrome(String word) { //<--changed the String[] to String
for (int i = 0; i < word.length(); i++) {
if (!(word.charAt(i) == word.charAt(word.length() - 1 - i))) { //Since [] will not work on Strings, using charAt() to do the same thing
return false;
}
}
return true;
}
// read word
public static String readWord(Scanner input) {
String word = input.nextLine();
word = word.toLowerCase();
return word;
}
// display results to the screen
public static void displayResults(boolean result) {
// display the results
String msg = "\nThat string ";
msg += (result == true) ? " IS " : " is NOT ";
msg += " a palindrome.\n";
System.out.println(msg);
}
// main function
public static void main(String[] args) {
// input scanner
System.out.print('\u000C');
System.out.println("Enter the word: ");
String s = readWord(new Scanner(System.in)); //Added a call to the readWord method and also passed a Scanner reference to the method and
//storing the read word in String s
boolean result = isPalindrome(s); //Added a call to the palindrome method and also passing the read string s to the method to find whether
//it is palindrome or not and storing the method return value in boolean result variable
displayResults(result); //Finally calling the displayResults with the result we got from isPalindrome() to display the appropriate message
}
}

Creating a random output from an user input array [closed]

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public class decisionMaker {
public static void main(String args[]) {
String option[] = new String[10];
// Output
for (int i = 0; i <= 9; i++) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the next option:");
option[i] = input.next();
System.out.println(" ");
}
for (int i = 0; i <= 9; i++) {
System.out.println("option: ");
System.out.println("option[i]+" ");
}
// Output
}
I'm trying to figure out how to add a count to the options, exit and end the program after entering a certain letter or number, and how to create a random output from the user input. I want it to give me one option that I had input at random. Can anyone help me with one or a few of these things. I'm trying to learn to code on my own, and I'm stuck on these.
Randomness
You can generate random numbers using java.util.Random;:
import java.util.Random;
public class SomeClass{
static Random rand = new Random();
public static void main(String args[]){
System.out.println(rand.nextInt());
}
}
About some broken code:
If you want to print out the value of a variable with System.out.println() then you need only type the variable without any quotation marks. The code you've written below will not compile:
System.out.println("option: ");
System.out.println("option[i]+" ");
Assuming that's what you want to do, it should instead be written as:
System.out.println("option: ");
System.out.println(option[i]);
Or even System.out.println("option: \n"+option[i]);
(The escape sequence \n when placed inside of quotation marks just indicates to the console to add a new line.)
Scanner:
Additionally, as nick zoum pointed out, your Scanner object should be initialized outside of the for loop, such as right underneath of the main() method.
Please comment below if you need clarification or if I misunderstood what you were looking for. It was very hard to understand your question.
You could try something like this:
public class DecisionMaker {
public static void main(String[] args) {
// output
Scanner scanner = new Scanner(System.in);
int size = getInt(scanner);
String option[] = new String[size];
for (int index = 0; index < size; index++) {
System.out.print("Enter the next option:");
option[index] = scanner.next();
}
int index = (int) (Math.random() * size);
System.out.println(option[index]);
scanner.close();
// output
}
public static int getInt(Scanner scanner) {
int size = 0;
while (size <= 0) {
if (scanner.hasNext()) {
if (scanner.hasNextInt()) {
size = scanner.nextInt();
}
}
if (size <= 0) {
System.out.println("The input: " + scanner.next() + " is not a valid value.");
}
}
return size;
}
}
How the program works:
The Scanner is initialized in the beginning and there is only
one instance of it.
Then the program will wait until the user inserts a valid number for
the size of options.
The next 5 lines were essentially copied from your code.
Finally we get a random Integer in the range of 0 - (size - 1) and print
the String of the array with that index.

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