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I'm a complete beginner at java and have entangled my methods

I'm making a horse-race themed program for my mom that compares the money taken in by her employees and ties it to a horse. I've created two methods which entirely rely on each other and have no idea how to call them into my main method. I, of course, also need to add a graphical element to this at some point, and figuring out how to make the program work with decimal integers would also be ideal. My main issue right now is I need to know how to call print3largest and inputs in my main method, or how to generally make this not a dumpster fire and maybe reduce it to less than 3 methods that aren't entangled like this.
I've searched through repository websites for hours now looking for a solution, but as I have no professional experience in any kind of programming I severely lack the terminology to find an answer, assuming anyone else is stupid enough to run into the same problem I have. I'm extremely limited in my programming knowledge, with java being the only thing I've ever messed with thanks to a course in high school. Sadly, that hardly helps as it was almost entirely through an interface that was essentially just scratch.
import java.util.Scanner;
class HorseComparison
{
public static void main(String[] args)
{
//no clue how to call print3largest or inputs here without ruining everything
}
static void print3largest(int arr[], int arr_size, String firsthorse, String secondhorse, String thirdhorse)
{
int i, first, second, third;
if (arr_size < 3)
{
System.out.print(" Invalid Input ");
return;
}
third = first = second = Integer.MIN_VALUE;
for (i = 0; i < arr_size ; i ++)
{
if (arr[i] > first)
{
third = second;
second = first;
first = arr[i];
}
else if (arr[i] > second)
{
third = second;
second = arr[i];
}
else if (arr[i] > third)
third = arr[i];
}
inputs(first, second, third);
System.out.println("The horse in the lead is " + firsthorse + " with " +
first + " dollars.");
System.out.println("The runner up is " + secondhorse + " with " +
second + " dollars.");
System.out.println("Third place is " + thirdhorse + " with " +
third + " dollars.");
}
static void inputs(int first, int second, int third)
{
Scanner sc = new Scanner(System.in);
int size;
System.out.println("How many horses are competing?");
size = sc.nextInt();
int[] arr = new int[size];
System.out.println("Enter the amount of money taken in by each horse (rounded to the nearest dollar and separated by spaces)");
//For reading the element
for(int i=0;i<size;i++) {
arr[i] = sc.nextInt();
int n = arr.length;
String firsthorse;
String secondhorse;
String thirdhorse;
System.out.println("Which horse has taken in "+ first +"?");
firsthorse = sc.toString();
System.out.println("Which horse has taken in "+ second +"?");
secondhorse = sc.toString();
System.out.println("Which horse has taken in "+ third +"?");
thirdhorse = sc.toString();
print3largest(arr, n, firsthorse, secondhorse, thirdhorse);
}
}
}
I want it to display the 3 highest amounts along with the input name of the horse tied to those amounts.

I don't feel like there really is enough information about what the program is intended to do for a clear, direct answer to be provided, but I will do my best.
First, what I would suggest, is you take a good look at this program and determine how you can separate out each responsibility. For example, do you really need to call inputs from print3largest, or could you possibly call this directly from your main?
Once you have established the intent of each function, consider making each function return a result. Generally speaking, you want parameters to be immutable. Learning functional programming habits now will help you down the road.
Here is what I would do:
Copy this file to a backup file.
Start a new Java project, create your class.
Write all of your display code. That is, develop the initial user experience. What inputs do you want to ask from the user? Capture those inputs.
Given those inputs, write your core algorithm, which currently appears to be primarily in print3largest. Return those results back to the caller.
Display your results back to the end user.
This might result in more functions, but that isn't a bad thing. I would also advise that you consider creating a separate class to hold some of this logic. This will give you an opportunity to learn about objects and separation of concerns.

you can call static methods directly by the method name
print3largest()
or you can use the classname before method name example
HorseComparision.print3largest() ```

Since both methods are static and so the Main method. Static methods can be called
Directly with method name, if you are calling from inside the class. Eg : print3largest(.. args), inputs(.. args)
call using ClassName.Method name. This can be used if you are calling method from outside or inside the class. Eg: HorseComparison.print3largest(.. args), HorseComparison.inputs(.. args)

Why is my basic rumor simulation program not working? [closed]

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My assignment
I have been tasked with attempting to code this program in Java. I've coded a program I think should work, but no matter what I input as the argument it says everyone has heard the rumor in every situation. I think it has something to do with skipping my while loops and me miswriting something else later on...? I'm completely lost, and because my attempts to troubleshoot what is being executed and what isn't have been failing I don't really know how to fix it. My attempt at coding the problem is below. I've tried to put in a lot of notes to help anyone trying to help me follow along, though I'm not sure if I have out everything down in the right etiquette; sorry if I messed up!
public class ProgrammingProblem1 {
public static void main(String[] args) {
int people = Integer.parseInt(args[0]) ;
//Obtains how many people not including Alice are at the party
boolean[] guests;
double averageheard = 0.0;
// This double will be used at the end to determine on average how many people heard the rumor.
double totalheard = 0.0;
// This double is used to help calculate how many people heard the rumor over all the iterations. Keeps track of the total people who knew the rumor throughout the permutations.
double percentsuccess = 0.0;
// This double will be used at the end to determine the percent of how many times the rumor was heard by everyone against how many loops there were.
double rumorsuccess = 0;
// This keeps track of how many times the rumor went all the way around.
double rumorfail = 0;
// This keeps track of how many time the rumor did not make it all the way around.
guests = new boolean[people];
//Fills the array with as many slots as there are people at the party. Guests is the array that stores if someone has heard the rumor or not.
int runtime = Integer.parseInt(args[1]);
// Guests is to figure out how many guests besides Alice are at the party and set them in an array, and Runtime is to figure out how many simulations you are meant to run.
if (people < 1 || runtime < 0){
//This is to check if the arguments were entered correctly.
System.out.println("You entered the arguments incorrectly. The amount of people at the party besides Alice must be at least two and the simulation must be run at least once.");
}else {
for ( int i = 0; i < runtime ; i++) {
// This is for doing however many iterations through are desired.
int heard = 0;
// This variable will be used at the end to determine if everyone has heard the rumor.
int current = 0 ;
// This ensures that we start with our first person ,"Bob", as the progintor of the rumor. Current is whoever is currently telling the rumor to someone else.
for (int l = 0; l < people; l++){
guests[l] = false; }
guests[0] = true ;
// This ensures that Bob already knows the rumor.
int next = (int)(Math.random() * people) ;
// This randomly selects the first person Bob asks about it. Next is the person we are telling the rumor to
while (current == next) {
// This makes sure that the guest we are doing isn't talking to themselves
next = (int)(Math.random() * people );
}
while ( !guests[next] ) {
// This makes the loop go on until the canidate the person it would tell has already heard it
guests[next] = true;
// This line makes whoever was just told the rumor now knows the rumor
int last = current;
// This keeps track of who the last person who said the rumor was
current = next;
// This is making the person we just told the rumor to our new rumor teller.
next = (int)(Math.random() * people);
// This finds a new person to be told the rumor
while (current == next || last == next ){
// This ensures that the person we tell the rumor to next will not be the person telling the rumor to or the person who told them the rumor.
next = (int)(Math.random() * people); }
}
for ( int j = 0; j < people; ++j) {
// This is to determine how many people heard the rumor before it was terminated.
if ( guests[j] == true){
heard = heard + 1;
}
}
if ( heard == people){
//This if statement will add a counter to rumorsuccess if every person was told the rumor, and to rumorfail if everyone didn't hear it.
rumorsuccess = rumorsuccess + 1;
}
else{
rumorfail = rumorfail + 1; }
totalheard = totalheard + heard;
//This is to tally up how many people heard the rumor in total.
}
percentsuccess = (rumorsuccess / (rumorsuccess + rumorfail)) * 100 ;
// This calculates the percent of times the rumor went all the way around to everyone
averageheard = (totalheard / runtime) ;
// This calculates the average amount of times the rumor made its way around
System.out.println("Steven Mikels 20782");
System.out.println("The amount of people in the room besides Alice are: " + people + ". The amount of times the simulation was run is: " + runtime);
System.out.println("The rumor was heard by everyone in the room " + percentsuccess + " percent of the time. The average amount of people who heard the rumor was: " + averageheard);
}
}
}
EDIT 1: I have updated the code to accommodate my updating of the == related error. I have a few new issues now that the code calculates how many people heard on average correctly, though the percentage of times everyone has succeeded doesn't seem to be working. Entering "3" and then any other number into the command line correctly gives 100% of times gone through everyone hears it. Unfortunately, entering any number of people greater than 3 means the code have 0% chance to go all the way around, which is false. Additionally, entering "2" as the first number seems to make the program stall out command prompt. After some testing, it seems the variable rumorfail and rumorsuccess are always equal to each other.
EDIT 2: I'm fairly certain that I've managed to fix my problem; the variables rumorfail and rumorsuccess needed to be a double! It was rounding the number up or down, resulting in the 0% or 100% marks. Unfortunately, I'm still have an issue where my program won't allow two to be the amount of people or else it freaks out. I'm testing for more reasons on why that may be right now, but didn't want people working on the other issue since it is already solved! Strangely, 0 executes the statement correctly and prints that an invalid number has been inputted, but 1 shares the same problem that 2 did.

Off the bat i see a couple typos:
Youre while statement
while ( guests[next] = false ) { is missing a "="
it should be written like this guests[next] == false or !guests[next]
you also did the same thing in this if statement if ( guests[j] = true){
it should be guests[j] == true
The reason for this extra "=" is that "==" is the comparing operator, and "=" is the operator to set something equal to, so when you do if(x=1) your checking wheter not x CAN be set equal to 1, not if it is equal to 1;
Otherwise your code looks like it would run and calculate, just fix these syntax errors.

Hangman that saves wrong guesses in array and prints them before each guess. also prints gameboard with "_" and correct guesses

so I've been studying Java for about 3 months and I am supposed to do a Hangman code using only arrays, loops, and if statements. the word to be guesses is read from another file and saved as a string. I have to be able to save the wrong guesses in an array. and after each guess print all the wrong guesses so far, as well as the gameboard with underscores for not guessed letters and the correct guesses of course in their place. here is my code so far :
for(int l = 0; l<wordlength;l++)
{
System.out.print("_");
}
System.out.println();
System.out.println("WRONG: ");
for(int c = 0; c<numofGuesses;c++)
{
System.out.println();
System.out.print("GUESS"+guessN+"/"+numofGuesses+": ");
char guess1=in.next().charAt(0);
char guess = Character.toUpperCase(guess1);
guessN = guessN+1;
for (int j = 0; j<wordlength;j++)
{
if (guess==guessword.charAt(j))
{
System.out.println("Great guess!");
System.out.print (guessword.charAt(j));
}
else
{
System.out.print("_");
WRONG[u]=guess;
u++;
}
}
if you guess A it prints correctly "A___" but then if you guess B after instead of printing "AB__" (the word to guess is ABLE) i get "B__" also the wrong array is not storing and printing all the wrong guesses each time. please help I've been trying for 5 days and that's all I did the entire day today and I couldn't get past this.

Because this sounds a lot like a homework assignment, I will give directions for solving this, but not provide a full working solution. Hopefully, seeing how one could1 go about approaching such a problem is enough of a step in the right direction to be able to solve it yourself.
Let's first think about what we need to do.
Read a word that needs to be guessed, say String toBeGuessed.
You did this. ✔
Keep track of the characters the player has guessed so far.
Keep track of the number of turns a player has gotten.
Keep track of if the word has been guessed (player won!).
Say that the number of guesses a player can make is fixed. This can be modeled using a constant:
/**
* Number of guesses a player can take.
*/
public static final int NUM_GUESSES = 10;
Now let's think about the main logic of our hangman game. It is good to first think about the structure of your program and only later actually implement it. When thinking of the program structure, we don't bother with specifics of the programming language of your choice yet. In pseudocode, it would be something like the following, maybe (let's indicate what you already have with ✔).
for turn from 1 upto NUM_GUESSES do ✔
show player what they guessed so far
show the gameboard
ask player for their new guess ✔
save player's guess and update internal state
check if the player won, let them know if they did
if player did not win
let them know
Right. So, we need to somehow store the guesses that a player made. Every guess is a character, and we know there will be at most NUM_GUESS guesses in total. A good option (and one that is suggested by your exercise) is an array!
/**
* Characters that have been guessed so far.
*/
private char[] guessed;
This can be initialized as follows, since we know the maximum number of guesses:
this.guessed = new char[NUM_GUESSES];
This gives us an array of NUM_GUESSES characters that are initialized to 0 (see here). Since users won't guess that character, we can use it to represent guesses that have not been done yet. Alternatively, we can keep track of the current turn of the player in a separate variable. Your choice!
In the following, I will not keep track of the current turn in a separate variable, just to show more of arrays and loops. It might be a fun exercise to change this to using an int turn variable!
show player what they guessed so far
Alright, this should be fairly straightforward now. We basically need to print the part of the guessed array that is not 0. That can be done using a loop, like so for example:
System.out.print("You so far guessed: ");
for (int i = 0; i < guessed.length; ++i) {
if (i > 0) {
System.out.print(", ");
}
if (guessed[i] != 0) {
System.out.print(guessed[i]);
} else {
break; // stop the loop as soon as we run into a 0
}
}
System.out.println(".");
This will print something like You so far guessed: a, b, c. when the player guessed those characters. See how we only print the comma when some other character was printed before?
show the gameboard
The next point of the program structure is trickier to get right. Let's think a bit about structure again.
for each character in toBeGuessed
if the character has been guessed
print it
else
print an underscore
Looping over every character of a word can be done as follows.
int length = toBeGuessed.length();
for (int i = 0; i < length; ++i) {
char character = toBeGuessed.charAt(i);
// do something with character here
}
How do you find if a character has been guessed yet? Well, by checking if it is stored in the guessed array. This again can be done using a loop. That loop will be very similar to the one we have written above, when showing what the player guessed so far. I think you should be able to figure that one out.
save player's guess and update internal state
We move on to the next point of the program structure. Say that we have a char guess that the player guessed. We need to store this in our array guessed. Where? Well, at the first open spot, that seems a reasonable choice. To find that one, let's use a loop again, and break the loop when we have found an open spot.
for (int i = 0; i < guessed.length; ++i) {
if (guessed[i] == 0) {
guessed[i] = guess;
break;
}
}
check if the player won, let them know if they did
What we need to know in order to see if the player won, is simply if the number of characters they guessed right is equal to the number of characters in toBeGuessed. You could modify the loop for showing the gameboard to not print characters, but count correct ones. Then at the end compare to toBeGuessed.length() and if they are equal, the player won.
if player did not win, let them know
This should be fairly easy, if you got the previous point working.
When you did all the above and stitched it together, you should have a working version of hangman. Your very own, something to be proud of!
Some tips and tricks:
you can implement most of the points described above as separate methods;
when you do so, you can write one main method that calls the other methods (this will make it easier to read your own code and make changes to it);
try to put as little code as possible in the main method.
Here is a little template that you can start from.
import java.io.PrintStream;
import java.util.Scanner;
public class HangMan
{
/** Number of guesses a player can take. */
public static final int NUM_GUESSES = 10;
/** Word to be guessed in a game of hangman. */
private String toGuess;
/** Letters that have been guessed so far. */
private char[] guessed;
/**
* Construct a new game of hangman, ready to be played.
*/
public HangMan(String toGuess)
{
this.toGuess = toGuess;
this.guessed = new char[NUM_GUESSES];
}
// your other methods go here
/**
* Read guesses from given input and print results to given output.
* Continues until guesses have run out, or word was guessed.
*/
public void play(Scanner in, PrintStream out)
{
for (int round = 0; round < NUM_GUESSES; ++round) {
showGuessedSoFar(out);
showGameBoard(out);
char guess = askGuess(in, out);
saveGuess(guess);
if (hasPlayerWon()) {
out.println("You won!");
return;
}
}
// at this point, player ran out of guesses and hence lost
out.println("You lost...");
}
/**
* The bit that runs our hangman game.
*/
public static void main(String[] args)
{
// read word to guess from arguments, with a default value
// you would probably insert your "read word from file" code here
HangMan game = new HangMan(args.length >= 1 ? args[0] : "ABLE");
// play a game, using system input and output
game.play(new Scanner(System.in), System.out);
}
}
Good luck!
TL;DR. Trying to teach one how to think about a problem and how to write code that executes the solution one thought of. Features some example code with arrays and loops.
1 This is only one possible solution, there are always many ways to solve a given problem.

Calculate Dice Roll from Text Field

QUESTION:
How can I read the string "d6+2-d4" so that each d# will randomly generate a number within the parameter of the dice roll?
CLARIFIER:
I want to read a string and have it so when a d# appears, it will randomly generate a number such as to simulate a dice roll. Then, add up all the rolls and numbers to get a total. Much like how Roll20 does with their /roll command for an example. If !clarifying {lstThen.add("look at the Roll20 and play with the /roll command to understand it")} else if !understandStill {lstThen.add("I do not know what to say, someone else could try explaining it better...")}
Info:
I was making a Java program for Dungeons and Dragons, only to find that I have come across a problem in figuring out how to calculate the user input: I do not know how to evaluate a string such as this.
I theorize that I may need Java's eval at the end. I do know what I want to happen/have a theory on how to execute (this is more so PseudoCode than Java):
Random rand = new Random();
int i = 0;
String toEval;
String char;
String roll = txtField.getText();
while (i<roll.length) {
check if character at i position is a d, then highlight the numbers
after d until it comes to a special character/!aNumber
// so if d was found before 100, it will then highlight 100 and stop
// if the character is a symbol or the end of the string
if d appears {
char = rand.nextInt(#);
i + #'s of places;
// so when i++ occurs, it will move past whatever d# was in case
// d# was something like d100, d12, or d5291
} else {
char = roll.length[i];
}
toEval = toEval + char;
i++;
}
perform evaluation method on toEval to get a resulting number
list.add(roll + " = " + evaluated toEval);
EDIT:
With weston's help, I have honed in on what is likely needed, using a splitter with an array, it can detect certain symbols and add it into a list. However, it is my fault for not clarifying on what else was needed. The pseudocode above doesn't helpfully so this is what else I need to figure out.
roll.split("(+-/*^)");
As this part is what is also tripping me up. Should I make splits where there are numbers too? So an equation like:
String[] numbers = roll.split("(+-/*^)");
String[] symbols = roll.split("1234567890d")
// Rough idea for long way
loop statement {
loop to check for parentheses {
set operation to be done first
}
if symbol {
loop for symbol check {
perform operations
}}} // ending this since it looks like a bad way to do it...
// Better idea, originally thought up today (5/11/15)
int val[];
int re = 1;
loop {
if (list[i].containsIgnoreCase(d)) {
val[]=list[i].splitIgnoreCase("d");
list[i] = 0;
while (re <= val[0]) {
list[i] = list[i] + (rand.nextInt(val[1]) + 1);
re++;
}
}
}
// then create a string out of list[]/numbers[] and put together with
// symbols[] and use Java's evaluator for the String
wenton had it, it just seemed like it wasn't doing it for me (until I realised I wasn't specific on what I wanted) so basically to update, the string I want evaluated is (I know it's a little unorthodox, but it's to make a point; I also hope this clarifies even further of what is needed to make it work):
(3d12^d2-2)+d4(2*d4/d2)
From reading this, you may see the spots that I do not know how to perform very well... But that is why I am asking all you lovely, smart programmers out there! I hope I asked this clearly enough and thank you for your time :3

The trick with any programming problem is to break it up and write a method for each part, so below I have a method for rolling one dice, which is called by the one for rolling many.
private Random rand = new Random();
/**
* #param roll can be a multipart roll which is run and added up. e.g. d6+2-d4
*/
public int multiPartRoll(String roll) {
String[] parts = roll.split("(?=[+-])"); //split by +-, keeping them
int total = 0;
for (String partOfRoll : parts) { //roll each dice specified
total += singleRoll(partOfRoll);
}
return total;
}
/**
* #param roll can be fixed value, examples -1, +2, 15 or a dice to roll
* d6, +d20 -d100
*/
public int singleRoll(String roll) {
int di = roll.indexOf('d');
if (di == -1) //case where has no 'd'
return Integer.parseInt(roll);
int diceSize = Integer.parseInt(roll.substring(di + 1)); //value of string after 'd'
int result = rand.nextInt(diceSize) + 1; //roll the dice
if (roll.startsWith("-")) //negate if nessasary
result = -result;
return result;
}

Custom Dice Generator

Okay so this is for homework. I don't want a complete answer, just someone to help nudge me in the right direction. I am fairly new to Java, so please take it easy :P Okay so my professor is having us do a Dice simulation program with OOP. This is just one portion of the entire problem, but it's the part I'm stuck on, so if you need more I can provide more. But the instructions say:Make a Roll function that will simulate rolling each die, and return the total
This function should only allow values between the appropriate range (i.e. if each die only has 4 faces, only numbers 1 - 4 should be allowed).
What I have so far for this particular function is this:
public double Roll()
{
for(int i = 0; i < numDice; i++)
{
double total = Math.random()*numFaces + 1;
}
return total;
I don't know where to go from here, and I don't know what really to do. This is my first programming class and it's way over my head :P So like I said, if I could just get pointed in the right direction (using dummy talk, cause I'm still having a hard time grasping this whole thing) that would be awesome. And I can provide more of the actual problem if need be.

Just noticed you used double , replace double with int or short. Look at the following tutorial.
http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Your also not so hot with naming conventions. Read this.
http://www.oracle.com/technetwork/java/javase/documentation/codeconvtoc-136057.html
You don't need to roll for each face, only for each dice. Do this.
Please note, for this you could use shorts as well.
public int roll() {
return new Random().nextInt(6) + 1; // Returns number between 1 and 6
}
If you want to roll multiple dice you could do this.
public int roll(int amount) {
int total = 0;
for(int i = 0; i < amount; i++) {
total += new Random().nextInt(6) + 1;
}
return total;
}

You're defining total inside the for loop, which makes it invisible outside it. Also, you're overwriting it (=) instead of adding to it (+=) on each die throw.
public double Roll()
{
double total = 0;
for(int i = 0; i < numDice; i++)
{
total += Math.random()*numFaces + 1;
}
return total;
}
I would also recommend to follow Java style and rename the method roll (methods start with a lowercase letter). The return type also strikes me as odd, I would probably use int in a similar situation.

You could create a class named Die to represent a die. This fits with OOP as 'die' would be one of your nouns. Now think of what configuration and behavior a Die might have. You may wish to have a Die have a configurable number of faces, but default to 6 if it isn't specified. You also want to be able to roll a die. Lets see what we have so far. Implementation left up to the reader.
public class Die {
public Die(){
this(6);
}
public Die(int faces){
//TODO: Write a constructor that takes number faces as an argument.
}
public int roll(){
//TODO: Implement a roll for this die, considering the number of faces.
}
}
Ok, so you have the beginning of a Die class. Now you might think, wouldn't it be cool if I could group die together as Dice (a set of dice if you will).
public class Dice {
public Dice(Die... dice){
//TODO: Implement constructor that takes an array of die objects.
}
public int roll(){
//TODO: Roll all the dice, sum and return the result.
}
}
Next you might think, man wouldn't it be sweet if I could treat Dice and a single Die as a single type, I mean they both can be rolled. Let us create an interface called Rollable that specified the roll behavior and have both Dice and Die implement it.
public interface Rollable {
int roll();
}
Then go back and change the class declarations to be.
public class Die implements Rollable
and
public class Dice implements Rollable
Now code that needs to roll things only needs to worry about Rollable instead of Die or Dice

First of all, you need to declare the total outside the for-loop. Then initialize it to zero.
Then, inside the for-loop. Increase the variable.
If numFaces should be able to be different for each die, you will need to get the value for it inside the for-loop, on each iteration.
Also, you should ask yourself: Which possible values do I want for the total variable? Should it be int or double?

You need to define total outside the for loop and then do total+=… inside the loop