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Thread: What's wrong with my integers?

  1. #1
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    Default What's wrong with my integers?

    Hello, I just started using Java last week. And I've decided to try to make my own guessing game without looking up a tutorial on how to do so. My problem is that, it's saying my ints cannot be resolved as variables. So here is my code!

    import java.util.Scanner;
     
     
    public class StringVariables {
     
    	public static void main(String [] args) {
    		int answer1 = your_first_guess;
    		int answer2 = your_second_guess;
    		int answer3 = your_last_guess;
     
    		Scanner user_input = new Scanner(System.in);
     
    		String your_first_guess;
    		System.out.println("You have three guesses left");
    		System.out.println("Please enter your first guess!");
    		your_first_guess = user_input.next();
    			if (answer1 != Math.random()){
    				System.out.println("You are wrong!");
    			}else{
    				System.out.println("You are rigtht!");}
     
    		String your_second_guess;
    		System.out.println("You have two guesses left!");
    		System.out.println("Please enter your second guess!");
    		your_second_guess = user_input.next();
     
     
    		String your_last_guess;
    		System.out.println("You have one guess left!");
    		System.out.println("Please enter your last guess!");
    		your_last_guess = user_input.next();
     
    	}
     
    }

    Thank you for your help.

    P.S. Please don't point out any other mistakes I would like to find them myself!
    Last edited by helloworld922; July 26th, 2013 at 10:57 PM. Reason: please use [code] tags


  2. #2
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    Default Re: What's wrong with my integers?

    Your program code is initiated sequentially, line by line. So what do you think happens when your IDE runs your the first statement in the main method of the code.

    //You are declaring these integer elements and then assigning them values from variables that have not been defined/initialized.
     
    int answer1 = your_first_guess;      //Variable answer1(initalized to 0 depending on your IDE) *gets*
                                        //variable your_first_guess (No type has been defined and has not been initalized)
    int answer2 = your_second_guess;  
    int answer3 = your_last_guess;

  3. #3
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    Default Re: What's wrong with my integers?

    Hi. Well first off they can't be resolved because you are trying to set them to a value that doesn't exist.

    You aren't creating space for a value named "your_first_guess" until you initialize it by declaring it a new type.
    Ex.. Bad
    int twoInt = oneInt;
    // blah blah
    // blah blah
    // blah blah
    int oneInt = 56;

    Ex.. Good
    int oneInt = 56;
    // blah blah
    // blah blah
    // blah blah
    int twoInt = oneInt;

    Post your progress and I will assist you every step of the way.

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    Default Re: What's wrong with my integers?

    Well I don't exactly have a value for the integers. So how would I make the integers the numbers the person guesses?

    Edit: AlexHail if you wouldn't mind adding me on skype so we could talk easier. Just pm me your skype if want to, no need though.

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    Member Zyrion's Avatar
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    Default Re: What's wrong with my integers?

    Quote Originally Posted by markch25 View Post
    Well I don't exactly have a value for the integers. So how would I make the integers the numbers the person guesses?
    Goal 1: I want to get the user's guess.
    Tip: Using I/O, get the users guess and store it inside an integer variable.

    Goal 2: I want to get a random number.
    Tip: Using the random class, using the method MATH.random() will generate a random number.

    Goal 3: I want to store that random number.
    Tip: Store it in the appropriate data type variable.

    Goal 4: Compare the users guess with the random number.
    Tip: Using an equality operator you can compare the two, then using a loop statement
    such as a do while loop, you can continue the game.


    Contact: JavaCottage@skype.com if you need any assistance as well.

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    Default Re: What's wrong with my integers?

    Firstly you must understand the types of variables to solve this problem.

    When you are getting input from the user, this information is stored in a memory space specified as a String which holds a combination of chars. We can't simply use this String for our problem because we are using operators designed for testing values of Integers.

    So I hope by now your human logic has sensed something... In order to test the values our user input gives us, we must first convert the input from a String type to an Integer type.

    Also when using Math.random(), this method returns a double value from 0.0 to 1.0 and I don't think its what you're looking for

  7. #7
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    Default Re: What's wrong with my integers?

    Quote Originally Posted by AlexHail View Post
    ...Also when using Math.random(), this method returns a double value from 0.0 to 1.0 and I don't think its what you're looking for
    With a little bit a manipulation it's a perfect method for this problem.

    Just remember that when using Math.random() from the java.lang.Math class is that it returns a static double value. So remember when comparing or casting a double to an int precision will be lost.

    Java API:
    Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0.
    But let's say you wanted a random integer between 1 and 100. Well since the method returns a value LESS than 1.0 you'll have to do three things. Multiple the return by 100, add by 1, and convert to int.

    int rnd = (int)(100 * Math.random() + 1);

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    Default Re: What's wrong with my integers?

    Why not just use nextInt in the Random class?
    Improving the world one idiot at a time!

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