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Thread: Newbie, why is my program printing output twice?

  1. #1
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    Default Newbie, why is my program printing output twice?

    hey guys, recently opened a java book and started coding, it was fun

    having problem with this password checker that i tried my hand at

    it prints output twice

    import java.util.*;
     
    public class SimplePassword {
     
    	public static void main(String[] args) {
     
    		//variables
    		Scanner myScanner = new Scanner(System.in);
    		String password = "swordfish";
    		String userinput;	
     
    		//runs once and then repeatedly while the password check returns false
    		do{
    			System.out.println("Write password ");
    			userinput = myScanner.next();	
    			checkPW(password, userinput);
    		}while(checkPW(password, userinput) == false);
     
    	} //end main
     
    	//comparison method
    	public static boolean checkPW(String password, String userinput){
     
    		if(password.equals(userinput)){
    			System.out.println("Access granted");
    			return true;
     
    		}
    		else
    		{
    			System.out.println("Access denied.");
    			return false;
    		}
     
    	} //end checkPW
    }// end class

    example output:

    Write password 
    monkeys
    Access denied.
    Access denied.
    Write password 
    swordfish
    Access granted
    Access granted

    Can you explain why it does this to me please?


  2. #2
    Super Moderator curmudgeon's Avatar
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    Default Re: Newbie, why is my program printing output twice?

    How many times are you call the checkPW method in your loop? Twice! Once inside of the loop itself, and once in the while boolean condition. I suggest you call it only once.

  3. The Following User Says Thank You to curmudgeon For This Useful Post:

    VikingCoder (November 2nd, 2012)

  4. #3
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    Default Re: Newbie, why is my program printing output twice?

    Thank you very much! Changed the while to this:

    while(!userinput.equals(password));

    now it works just fine :3

  5. #4
    Super Moderator curmudgeon's Avatar
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    Default Re: Newbie, why is my program printing output twice?

    Great, glad you've got it to work!

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