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Thread: Scanner Issues: Read for more detail, thanks.

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    Member Staticity's Avatar
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    Default Scanner Issues: Read for more detail, thanks.

    while(a < amount){
     
    int num1 = 2 + (int)(Math.random()*23);
    int num2 = 2 + (int)(Math.random()*23);
    int num3 = 2 + (int)(Math.random()*23);
    int num4 = 2 + (int)(Math.random()*23);
     
    String answer = null;
     
    if(num1*num4 > num2*num3){
    	answer = ""+num1+"/"+num2+"";
    }
     
    else if(num1*num4 < num2*num3){
    	answer = ""+num3+"/"+num4+"";
    }
     
    System.out.println("The larger of " + num1 + "/" + num2 + " or " + num3 + "/" + num4 + " is");
     
    	String reply = scan.next();
     
    	if(reply == answer){
    	System.out.println("Correct!");
    	correct++;
    	score += 5;
    }
    	else{
    	System.out.println("Wrong!");
    	wrong++;
    	score -= 9;
    }
    	amount--;
    }

    This piece of my code determines whether a fraction is greater than another using cross multiplying. The user must decide which fraction is the larger value. In order to place "/" into the answer, I converted the "reply" and "answer" variables into Strings. However, the output comes out like so:
    ---------------------------------
    The larger of 4/3 and 10/3 is
    10/3
    Wrong!
    ---------------------------------
    I even tried adding - "System.out.println(answer); - and placed that exact answer into the line. But my answer was still wrong. Can anyone help me understand some more about Scanners, and how they work? I'm not quite sure why the program keeps returning "Wrong!" to me when I am clearly putting in the correct answer. Thanks in advance!
    Last edited by Staticity; September 7th, 2011 at 09:41 PM.
    Simplicity calls for Complexity. Think about it.


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    Member Staticity's Avatar
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    Default Re: Scanner Issues: Read for more detail, thanks.

    I solved the issue by changing the "==" to .equals().
    Simplicity calls for Complexity. Think about it.

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    Default Re: Scanner Issues: Read for more detail, thanks.

    Concatenating the empty Strings is an abuse of your powers.
    Improving the world one idiot at a time!

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    Default Re: Scanner Issues: Read for more detail, thanks.

    Quote Originally Posted by Staticity View Post
    I solved the issue by changing the "==" to .equals().
    This is a common error
    Please use [highlight=Java] code [/highlight] tags when posting your code.
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