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Thread: For loop to create string.

  1. #1
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    Default For loop to create string.

    Hi, i'm trying to do a hangman game for my home task, and i got a few problems
    the first problem is: How can i return a string from for loop?

    Here is what i got so far:
    for (int i = 0; i < userWord.length(); i++) {
      if (userGuess.equals(Character.toString(userWord.charAt(i)))) {
         System.out.print(userGuess.toUpperCase() + " ");
      } else {
        System.out.print("_ ");
      }
    }

    When the userWord is "apple" and userGuess is "a" then it prints " A _ _ _ _ ",
    the next time user guess something for example "w" it prints " _ _ _ _ _ "


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    Default Re: For loop to create string.

    I'm assuming you aren't using arrays yet, and that's fine. If you are and would like to explore that approach, say so. For an approach that doesn't use an array, then the current result will change from:

    "_ _ _ _ _"

    to

    "A _ _ _ _"

    then when 'w' is guessed the current result will remain unchanged,

    "A _ _ _ _"

    So compare each character in the word to be guessed with the user's guess and fill in any correct guesses in the current result. The currentResult is a String object (which is immutable, by the way) that changes each time a correct guess is made. You can use the String methods to make this happen, so review the String API page.

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    Default Re: For loop to create string.

    I'm familiar with arrays and all the tried letters are saved to ArrayList. With a little help from my dear friend google, i came up with this:
    		for (int i = 0; i < userWord.length(); i++) {
    			for (String a : allLetters) {
    			if (a.equals(Character.toString(userWord.charAt(i)))) {
    				System.out.print(a.toUpperCase() + " ");
    			} 
    			if (!a.equals(Character.toString(userWord.charAt(i)))) {
    				System.out.print("_ ");
    			}
    		}	
    		}
    		System.out.println();
    	}
    Then this is the result:
    All the letters: [A, P, L, E] ( i print this out just for test )
    A _ _ _ _ P _ _ _ P _ _ _ _ L _ _ _ _ E
    now i get messed up word i'm thinking i must take the "sysout("_ ") out from the second for loop ? if so, then how ?

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: For loop to create string.

    If the condition in the second if is the negative of the condition in the first if, the code should use an else:
      if (x == 6} {
        //  do this
      }
      if (x != 6) {  //  this statement is confusing and could be an error
        // do that
      }
     
    //  vs
     
      if (x == 6) {
        // do this
      } else {       // this is clearer  and won't be an error
       // do that
      }
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    Thank you Norm for clearing that for me, but the end result stays the same as before.

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    Default Re: For loop to create string.

    Can you post an example of what the code outputs now and an example of what you want the output to be.
    For example:
    Current: A____
    Desired: Ax___
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    When i try to guess word "apple" then everytime i guess a letter the "_" adds in that word..
    my current output is : A _ _ P _ P _ _ _ _ "
    but what i desire is : "A P P _ _ "

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    Default Re: For loop to create string.

    Can you make a small, complete program that compiles and executes for testing? It just needs to define allLetters and userWord and nothing else and then use the nested for loops in post#3
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    Here is the small program [Java] help - Pastebin.com , tho i'm using TextIO to make user input easier.

  10. #10
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    Default Re: For loop to create string.

    Sorry, I don't go to other sites, can you post the code for a small test program here? Make a small testing program, Not the full program you are working on.

    Can you explain when you want to print a letter and when print a "-"?

    The inner loop will always print something for all the letters in allLetters.
    If there are 26 letters, the inner loop will print 26 times.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    public class Test {
     
            public static ArrayList<String> allLetters = new ArrayList<String>();
            public static String userWord, userGuess;
     
            public static void main(String[] args) {
                    System.out.println("userWord");
                    userWord = TextIO.getlnString().toUpperCase();         
                    boolean game = true;
                    while (game == true) {
                            System.out.println("userGuess");
                            userGuess = TextIO.getlnString().toUpperCase();
                            allLetters.add(userGuess);
                            test();
                    }
     
            }
     
            public static void test() {
                    for (int i = 0; i < userWord.length(); i++) {
                            for (String t2heke : allLetters) {
                                    if (t2heke.equals(Character.toString(userWord.charAt(i)))) {
                                            System.out.print(t2heke.toUpperCase() + " ");
                                    } else {
                                            System.out.print("_ ");
                                    }
                            }
                    }
                    TextIO.putln();
            }
    }

    (I'm using TextIO for easier input) I want to print letter when user guesses the right letter and the "_" when the letter doesnt match the one in word.

  12. #12
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    Default Re: For loop to create string.

    Please add code that assigns values to the userWord and the allLetter variables so the code can be compiled and executed WITHOUT needing any user input. The code should contain all that is needed to be able to call the test() method.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    public class Test {
     
    	public static ArrayList<String> allLetters = new ArrayList<String>();
    	public static String letters[] = { "p", "e", "l", "a", "c", "d" };
    	public static String userWord, userGuess;
     
    	public static void main(String[] args) {
    		userWord = "apple";
    		System.out.println("userWord is: " + userWord);
    		for (int i = 0; i < letters.length; i++) {
    			userGuess = letters[i];
    			System.out.println("userGuess is: " + userGuess.toUpperCase());
    			allLetters.add(userGuess);
    			test();
    		}
    	}
     
    	public static void test() {
    		for (int i = 0; i < userWord.length(); i++) {
    			for (String t2heke : allLetters) {
    				if (t2heke.equals(Character.toString(userWord.charAt(i)))) {
    					System.out.print(t2heke.toUpperCase() + " ");
    				} else {
    					System.out.print("_ ");
    				}
    			}
    		}
    		System.out.println();
    	}
    }

    right now the userWord is "apple" and the userGuess is taken from string array called letters
    I'm sorry if this is not the program you wanted :\

  14. #14
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    Default Re: For loop to create string.

    Can you explain when you want to print a letter and when print a "-"?

    There should be one character printed for each letter in userWord. The inner loop should only print ONE character: either the letter or a "-". The logic needs to be changed so that only one character is printed.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    public class Test {
     
    	public static ArrayList<String> allLetters = new ArrayList<String>();
    	public static String letters[] = { "p", "e", "l", "a", "c", "d" };
    	public static String userWord, userGuess;
            public static boolean found;
     
    	public static void main(String[] args) {
    		userWord = "apple";
    		System.out.println("userWord is: " + userWord);
    		for (int i = 0; i < letters.length; i++) {
    			userGuess = letters[i];
    			System.out.println("userGuess is: " + userGuess.toUpperCase());
    			allLetters.add(userGuess);
    			test();
    		}
    	}
     
    	public static void test() {
    		for (int i = 0; i < userWord.length(); i++) {
                              found = true;
    			for (String t2heke : allLetters) {
    				if (t2heke.equals(Character.toString(userWord.charAt(i)))) {
    					System.out.print(t2heke.toUpperCase() + " ");
                                              found = false;
    				} 
    			}
                                  if (found) {
                                    System.out.print("_ ");
                               }
    		}
    		System.out.println();
    	}
    }

    if i add boolean found in it and do the following then it works, but why and how? is there another way to do this ?

  16. #16
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    Default Re: For loop to create string.

    That looks like it does what you want. Why are you asking for another way to do it? That looks like a good way.

    The inner loop is a search loop. You only want a "-" to print if no match is found. To remember if a match was found the code uses a boolean.
    Normal English would use the variable found differently. Initialize it to false and set true when the match is found. If Not found, then print the "-"

    The variable would be named: noMatch for the way the code uses it.
    If you don't understand my answer, don't ignore it, ask a question.

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    clyxee (December 11th, 2013)

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    Default Re: For loop to create string.

    It was pretty confusing, that's why i asked if there's other ways to do it Thank you Norm
    Now i have another question: How can i compare the end result with the original word, to stop the game ?

  19. #18
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    Default Re: For loop to create string.

    Build a String in addition to printing the letters/"-" and compare it to the word.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    How should i do that ? give a string and then replace letters or how ?

  21. #20
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    Default Re: For loop to create string.

    One easy way is to use concatenation:
    String x = ""; // Define empty String
    ...

    x += "-"; // build String using concatenation
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: For loop to create string.

    Oh my god i got it Thank you so much Norm !!

  24. #22
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    Default Re: For loop to create string.

    Glad you got it working.
    If you don't understand my answer, don't ignore it, ask a question.

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