public void processLightClick(int row, int col) {
states[row][col] = !states[row][col];
if(states[row][col] = true){
lights[row][col].setFill(ON_PAINT);
}
else if(states[row][col] = false){
lights[row][col].setFill(OFF_PAINT);
}
turns++;
System.out.println(row+":"+col);
status.setText("Turn Number " + turns);
}
This is the code I have. I'm trying to get it to toggle states and colors each time a specific square is pressed but the paint stays the same and doesn't toggle the state back and forth when I press the same square twice
You are using an assignment operator "=" instead of a comparison operator "==" in your if-statement. Try this.
public void processLightClick(int row, int col) {
states[row][col] = !states[row][col];
if(states[row][col] == true){
lights[row][col].setFill(ON_PAINT);
}
else if(states[row][col] == false){
lights[row][col].setFill(OFF_PAINT);
}
turns++;
System.out.println(row+":"+col);
status.setText("Turn Number " + turns);
}
As user2615117 pointed out, you are not using the comparison operator, but the assignment operator. Here, however, I also would use the ternary operator to make the code more concise:
lights[row][col].setFill((states[row][col] == true) ? ON_PAINT : OFF_PAINT);
Another possible improvement would be to have a single array of Light objects which contain both the state and the paint of the light.
Related
I am a noob in Java and programing and I am making an app where the user is trying to guess a city based on a picture. The user sees a picture of the city and has three buttons under the picture with different answers in them. The pictures are randomized from an array and the buttons text changes so that atleast one of the buttons has the correct answer. I want a TextView with "correct" to show if user is correct and one with "incorrect" to show if user is wrong. The text is showing up when pressing any button and not when the button with the correct text is pressed. So this is what I have tried and am stuck on. And yes I know I have many mistakes in my code, such as names of methods and so. I will change these later.
I have three booleans that are set to false, they are representing which button is pressed. You will understand more later.
Boolean test1 = false;
Boolean test2 = false;
Boolean test3 = false;
In main i have three buttons and they all call on the checkanswer function. Also they all turn their own boolean to true there, which u will se why soon. Example of one of the buttons.
btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
test1 = true;
checkanswer();
}
});
So here is the checkanswer function
public void checkanswer() {
DisplayRandomImage();
//Giving three strings random city names from the "cities" array.
Random rndBtnTxt = new Random();
String randomCity1 = cities[rndBtnTxt.nextInt(cities.length)];
String randomCity2 = cities[rndBtnTxt.nextInt(cities.length)];
String randomCity3 = cities[rndBtnTxt.nextInt(cities.length)];
//Setting the random city names to the three different buttons.
btn1.setText(randomCity1);
btn2.setText(randomCity2);
btn3.setText(randomCity3);
//takes the picked image from the "DisplayRandomImage" method.
String str = String.valueOf(pickedImg);
//Tells what to call the different pictures, they are known as numbers make sure they are given names instead.
if (pickedImg == 0)
str = "venice";
if (pickedImg == 1)
str = "new york";
//If-statement checking so that atleast one button has the correct answer.
if (randomCity1 != str || randomCity2 != str || randomCity3 != str) {
Random rndbtn = new Random();
Button x = btnArray.get(rndbtn.nextInt(btnArray.size()));
//Sets one of the three buttons so that it has the correct answer.
x.setText(str);
}
//See where the correct answer is
String buttonText1 = btn1.getText().toString();
String buttonText2 = btn2.getText().toString();
String buttonText3 = btn3.getText().toString();
//check if the button that the user pressed has the correct answer
if (test1.equals(true) && buttonText1.equals(str)){
CorrectAnswer();
test1 = false;
}
if (test2.equals(true) && buttonText2.equals(str)){
CorrectAnswer();
test2 = false;
}
if (test3.equals(true) && buttonText3.equals(str)){
CorrectAnswer();
test3 = false;
}
else
WrongAnswer();
}
I am not sure what I am doing wrong here. For example the "test1" is set to True when I press "btn1" and if "buttontext1" equals to the same as "str" does it should work. But for some reason it seems randomised which of the three buttons calls for the CorrectAnswer method. What am I doing wrong here?
Can we see CorrectAnswer? Also,
right off the bat, I noticed that instead of using test1, test2 and test3 to indicate which button was pressed, you can just pass some sort of argument into checkAnswer, like int button.
So onClick would look like this for the first button, and subsequent buttons by incrementing the 1:
public void onClick(View v) {
checkanswer(1);
}
and checkanswer would look like this:
public void checkanswer(int button) {
... (previous stuff) ...
//check if the button that the user pressed has the correct answer
if (button == 1 && buttonText1.equals(str)){
CorrectAnswer();
}
if (button == 2 && buttonText2.equals(str)){
CorrectAnswer();
}
if (button == 3 && buttonText3.equals(str)){
CorrectAnswer();
}
else
WrongAnswer();
}
So try this out.
Its pretty hard to tell where the bug is, if you only show us pieces of the full code.
Mistakes could be e.g. in CorrectAnswer()...
I would recommend binding onlick-listeners to your buttons instead of changing booleans.
Check this out here: https://developer.android.com/reference/android/widget/Button
Additionally I noticed another mistake:
randomCity1 != str || randomCity2 != str || randomCity3 != str
This will return true if at least one of the Strings does not contain the right answer
You probably want to enter the if-Statement, when there isnt already a button with the correct answer.This is what you would like to use:
randomCity1 != str && randomCity2 != str && randomCity3 != str
EDIT: Check out the answer of Barcode for another example of using onClicklisteners.
Thank you both for answering the question, i have found a way to complete this problem:
public void testingMethod(int button){
switch(button){
case 1:
if (buttonText1 == str)
CorrectAnswer();
else
WrongAnswer();
break;
case 2:
if (buttonText2 == str)
CorrectAnswer();
else
WrongAnswer();
break;
case 3:
if (buttonText3 == str)
CorrectAnswer();
else
WrongAnswer();
break;
}
}
And since you were wondering how the method CorrectAnswer looked like here it is, yes I know it's probably unnecessary having this method but I am noob after all.
public void CorrectAnswer() {
findViewById(R.id.txtIncorrect).setVisibility(View.GONE);
findViewById(R.id.txtCorrect).setVisibility(View.VISIBLE);
}
I've a little problem.
Myself and a few friends were playing poker yesterday but we didn't have chips so I decided to start writing a program for that [Without Cards, just Chips].
In my code I have two main variables in the Game Object.
private int id;
private long bank;
I have a different file called Aside in which I can do different calculations.
In the code below I am trying to compare all instance bank variables to see if all the banks matched [In this case this will mean a new card can be drawn, otherwise users will have to keep to either raise or fold].
Is there a way of writing this in an easier term:
package poker;
import java.util.ArrayList;
public class Aside
{
public boolean compareBanks(ArrayList<Game> x)
{
ArrayList<Game> players = new ArrayList(x);
if(players.get(0).getBank() == players.get(1).getBank() && players.get(0).getBank() == players.get(2).getBank()
&& players.get(1).getBank() == players.get(2).getBank())
{
return true;
}
return false;
}
}
Later I use this here:
while(aside.compareBanks(players))
But the loop keeps going.
I'm fairly intermediate in programming so go easy on me with mistakes.
Thank you for your time.
P.S: This is NOT a code dump.
while(aside.compareBanks(players))
{
for(Game x : players)
{
if(x.hasPayedBid() == true)
{
System.out.println("Player : " + x.getName() + " [Call, Raise, Fold]:");
action = in.nextLine();
if(action.equalsIgnoreCase("call"))
{
break;
}else if(action.equalsIgnoreCase("raise"))
{
System.out.println("How much are you raising? $");
int raise = in.nextInt();
table += raise;
x.raise(raise);
}else
{
x.fold();
}
}
}
in.nextLine();
for(Game x : players)
{
System.out.println(x.toString() + "\n");
}
}//End While
You can do it using java-8 Stream API something like this
return players.stream().allMatch(p -> p.getBlank().equals( players.get(0).getBalnk()))
However if you will use while(aside.compareBanks(players)) and all elements of the list have equal blank value, your while loop will never stop. It is the same as while(true). So in this case you probably need to use if(aside.compareBanks(players)) or in case of equal blank values change them.
Try this
long bankValue=0;
For(Game player: players){
bankValue+=player.getBank();
}
if(bankValue==(players.get(0).getBank()*players.size)){
return true;}
else return false;
I have four methods that check whether or not a given grid location is next to an occupied location (value of 1). The grid is assumed to wrap around, ie, if in a 50x50 grid[0][1] is the given location and grid[49][1] is occupied, the method should return true/ My checkNorth and checkEast method are working fine, but I get an ArrayIndexOutofBoundsException: -1 error for either the south or west methods every time I run the program. I checked my math and I think it should work - am I using the modulo incorrectly, or am I missing something else?
EDIT: Clarified the wrapping criterion, word use correction.
boolean checkWest(int indexA, int indexB)
{
if (indexA-1 > 0)
{
if (grid[indexA-1][indexB] == 1)
{
return true;
}
}
if (indexA-1 < 0)
{
if (grid[(indexA-1)%width][indexB] == 1)
{return true;}
else return false;
}
return false;
}
I see a couple problems. First, Java arrays are zero-indexed, which means that the first element is at index 0. So it's okay to check grid[indexA-1][indexB] when indexA-1 is equal to 0. Second, you're not properly handling when indexA equals 0. Here is my implementation. I also simplified the logic a bit.
boolean checkWest(int indexA, int indexB)
{
if (indexA > 0)
return grid[indexA - 1][indexB] == 1;
else
return grid[width + indexA - 2][indexB] == 1;
}
EDIT: I'm pretty sure I butchered the math with the second return statement. It should be right now...
So I'm making a TicTacToe-program, and I made a method for checking if there are 3 pieces in a row, to check if the game is over or not.
public boolean hasWon() {
if (tictac[0][0].equals(tictac[1][0]) && tictac[0][0].equals(tictac[2][0]) && tictac[1][0].equals(tictac[2][0])) { //Vertical
return false;
} else if (tictac[0][1].equals(tictac[1][1]) && tictac[0][1].equals(tictac[2][1]) && tictac[1][1].equals(tictac[2][1])) { //Vertical
return false;
} else if (tictac[0][2].equals(tictac[1][2]) && tictac[0][2].equals(tictac[2][2]) && tictac[1][2].equals(tictac[2][2])) { //Vertical
return false;
} else if (tictac[0][0].equals(tictac[0][1]) && tictac[0][0].equals(tictac[0][2]) && tictac[0][1].equals(tictac[0][2])) { //Horizontal
return false;
} else if (tictac[1][0].equals(tictac[1][1]) && tictac[1][0].equals(tictac[1][2]) && tictac[1][1].equals(tictac[1][2])) { //Horizontal
return false;
} else if (tictac[2][0].equals(tictac[2][1]) && tictac[2][0].equals(tictac[2][2]) && tictac[2][1].equals(tictac[2][2])) { //Horizontal
return false;
} else if (tictac[0][0].equals(tictac[1][1]) && tictac[0][0].equals(tictac[2][2]) && tictac[1][1].equals(tictac[2][2])) { //Diagonal
return false;
} else if (tictac[0][2].equals(tictac[1][1]) && tictac[0][2].equals(tictac[2][0]) && tictac[1][1].equals(tictac[2][0])) { //Diagonal
return false;
} else {
return true;
}
}
The problem here is, with these conditions I figured if, say, all of the indexes "in a row" where f.ex. X, " X X X " it would be a win for the player X. However, my program calls for a winner if any kind of piece fill 3 in a row, f.ex. " X O X " would end the game, which obviously is wrong.
Have I misunderstood .equals?
EDIT: after the wonderful feedback, is there a way that I can make the if-statements to ignore blank spaces (" ")?
You should consider creating a class, Board. Have this class provide an interface that includes getLines. This should return a List<Line>. There are eight lines in a tic tac toe board: three horizontal, three vertical, two diagonal. Create a method isWin(String player, Line line). Return true or false based on whether the count of the player's marker in the cells of the line is three.
I would guess you can write the whole thing in the same amount of space as the horrible nested if with all its inscrutable && clauses, and the functioning will be obvious. (This is also good practice for encapsulation.)
Your prog returns true if all three values on some line are the same. So, it won't return true on XOX. But would on OOO, XXX and SpaceSpaceSpace.
The first two are both OK, for if you check after a move, only the last mover could have three in a line and win. But three spaces are a problem. In every if you should check the first cell for not having space.
It is longer, but if you use the advice of #ajb, you'll even shorten the prog.
As for structuring, I would advice more simple way than that of #syrion. Make an array lines[5,3,2]. It has 5 lines, 3 cells for every line and 2 coords for every cell. And you can do the check in two inserted loops. It is not a Java way to do things, but you can take it as a first step. Or you could move immediately to a more readable structure - a list of 5 x lines= array of Cell = pair of coordinates. I don't know which one is more simple for you.
Still working on my sudoku solver, I have once again run into some trouble. I have gotten the sudoku solver to work, however whenever I attempt to solve a really "hard" sudoku board, my solver tells me there are no possible solutions, due to a stack overflow error. And yes, I know for a fact that these boards DO have a solution.
I am using the brute force algorithm -- I start at square one (or [0][0] if you prefer) and insert the first legal value. I then do a recursive call to the next square, and so on. If my function has not gone through the entire board, and finds there are no possible legal values, it moves to the previous square and attempts to increment the value there. If that fails, it moves further back. If it ends up at square one with no possible solutions, it exits.
I admit my code is not pretty and probably quite inefftective, but please keep in mind that I am a first year student trying to do my best. I don't mind comments on how to effectivize my code though :)
For squares without a final predefined number, here's the solver function:
public void fillRemainderOfBoard(Square sender){
try {
while(true){
if(currentPos > boardDimension){
if(previous != null){
this.setNumrep(-1);
this.setCurrentPos(1);
previous.setCurrentPos(previous.getCurrentPos()+1);
previous.fillRemainderOfBoard(this);
return;
} else if(sender == this){
this.setCurrentPos(1);
} else {
break;
}
}
if((thisBox.hasNumber(currentPos)) || (thisRow.hasNumber(currentPos)) || (thisColumn.hasNumber(currentPos))){
currentPos++;
} else {
this.setNumrep(currentPos);
currentPos++;
break;
}
}
if(this != last){
next.setNumrep(-1);
next.fillRemainderOfBoard(this);
} else {
return;
}
} catch (StackOverflowError e){
return;
}
}
In my code, the numrep value is the value that the square represents on the board. The currentPos variable is a counter that starts at 1 and increments until it reaches a legal value for the square to represent.
For squares with a predefined number, here's the same function:
public void fillRemainderOfBoard(Square sender){
if((sender.equals(this) || sender.equals(previous)) && this != last){
System.out.println(next);
next.fillRemainderOfBoard(this);
} else if (sender.equals(next) && this != first) {
previous.fillRemainderOfBoard(this);
} else {
System.out.println("No possible solutions for this board.");
}
}
Now, my problem is, like I said, that the function DOES solve sudokus very well. Easy ones. The tricky sudokus, like those with many predefined numbers and only a single solution, just makes my program go into a stack overflow and tell me there are no possible solutions. I assume this indicates I am missing something in the terms of memory management, or the program duplicating objects which I call in my recursive functions, but I do not know how to fix them.
Any help is greatly appreciated! Feel free to pick on my code too; I'm still learning (oh, aren't we always?).
___________________EDIT________________
Thanks to Piotr who came up with the good idea of backtracking, I have rewritten my code. However, I still cannot get it to solve any sudoku at all. Even with an empty board, it gets to square number 39, and then returns false all the way back. Here is my current code:
public boolean fillInnRemainingOfBoard(Square sender){
if(this instanceof SquarePredef && next != null){
return next.fillInnRemainingOfBoard(this);
} else if (this instanceof SquarePredef && next == null){
return true;
}
if(this instanceof SquareNoPredef){
currentPos = 1;
if(next != null){
System.out.println(this.index);
for(; currentPos <= boardDimension; currentPos++){
if((thisBox.hasNumber(currentPos)) || (thisRow.hasNumber(currentPos)) || (thisColumn.hasNumber(currentPos))){
continue;
} else {
System.out.println("Box has " + currentPos + "? " + thisBox.hasNumber(currentPos));
this.setNumrep(currentPos);
System.out.println("Got here, square " + index + " i: " + numrep);
}
if(next != null && next.fillInnRemainingOfBoard(this)){
System.out.println("Returnerer true");
return true;
} else {
}
}
}
if(next == null){
return true;
}
}
System.out.println("Returning false. Square: " + index + " currentPos: " + currentPos);
return false;
}
I had to complicate things a bit because I needed to check whether the current object is the last. Hence the additional if tests. Oh, and the reason I am using boardDimension is because this sudoku solver will solve any sudoku -- not just those 9 by 9 sudokus :)
Can you spot my error? Any help is appreciated!
So your problem lies here:
previous.fillRemainderOfBoard(this);
and here
next.fillRemainderOfBoard(this);
Basically you have too many function calls on the stack because you are going forward and backward multiple times. You are not really returning from any call before answer is found (or you get StackOverflowError :)). Instead of increasing stack size by using recursive function try to think how to solve problem using a loop (pretty much always loop is better than recursive solution performance wise).
Ok so you can do something like this (pseudo code):
boolean fillRemainderOfBoard(Square sender){
if (num_defined_on_start) {
return next.fillRemainderOfBoard(this);
} else {
for (i = 1; i < 9; ++i) {
if (setting i a legal_move)
this.setCurrentPos(i);
else
continue;
if (next.fillRemainderOfBoard(this))
return true;
}
return false;
}
The stack size will be ~81.