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Thread: Looping doesn't change value

  1. #1
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    Default Looping doesn't change value

    Okay guys so here is my problem.
    Write a program that asks the user for the low and high integer in a range of integers. The program then asks the user for integers to be added up. The program computes two sums:

    The sum of integers that are in the range (inclusive),
    and the sum of integers that are outside of the range.
    The user signals the end of input with a 0.

    Your output should look like this:

    Sample input/output

    In-range Adder Low end of range: 20
    High end of range: 50
    Enter data: 21
    Enter data: 60
    Enter data: 49
    Enter data: 30
    Enter data: 91
    Enter data: 0
    Sum of in range values: 100
    Sum of out of range values: 151

    This is my assignment and below is my code.

     
    import java.util.Scanner;
    class InRangeAdder {
      public static void main(String[] args) {
        Scanner scan = new Scanner (System.in);
        int low, high, data=1, rangesum=0, outrangesum=0;
        System.out.println("Low end of range:");
        low = scan.nextInt();
        System.out.println("High end of range:");
        high = scan.nextInt();
        while (data!=0) {
          System.out.println("Enter data:");
          data = scan.nextInt(); 
        } 
        if (data >= low && data <= high) {
          rangesum= rangesum+data;
        } 
        if (data > high || data < low) {
          outrangesum=outrangesum+data;
        }
      System.out.println("Sum of in range values: " +rangesum);
      System.out.println("Sum of out of range values: " +outrangesum);
    }
    }

    The problem is that the program simply gives an output of 0 for both "rangesum" and "outrangesum". I don't quite understand why that is.
    Also i have a quick question, the program needs me to end the program when the value of data is 0 but in order to initialize it I need to give it a value. Usually I would give it a value of 0 like I have for rangesum and outrangesum but if I do the program does not run till the loop as it considers the value of data to be 0 and ends the program right away. What would be a work around to this and when do I need to have a value to initialize an integer? for example, I do not need a value for low and high. Is this because the program recognizes that a value is going to be defined but cannot do that for the other integers as they are inside a loop?

    Thanks so much and any feedback is greatly appreciated.
    Cheers.


  2. #2
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    Default Re: Looping doesn't change value

    Also i have a quick question, the program needs me to end the program when the value of data is 0 but in order to initialize it I need to give it a value. Usually I would give it a value of 0 like I have for rangesum and outrangesum but if I do the program does not run till the loop as it considers the value of data to be 0 and ends the program right away.
    then equate it to a number other than zero.


    The problem is that the program simply gives an output of 0 for both "rangesum" and "outrangesum". I don't quite understand why that is.
    First, look at this statement in your code:
        while (data!=0) {
          System.out.println("Enter data:");
          data = scan.nextInt(); 
        }
    it just keep over writing the value of your data variable. and the only way to terminate the loop is when it handles a zero value. in short, at the end of your loop, the value of your data variable is zero for sure.

    then look at this statement in your code:
        if (data >= low && data <= high) {
          rangesum= rangesum+data;
        } 
        if (data > high || data < low) {
          outrangesum=outrangesum+data;
        }
    you do the checking and storing outside the while loop, hence the value of data in that part of your code is zero for sure since the while loop only terminates when the data is zero that is why you always got a zero value.

    Try to put those checking inside your loop that might solved your problem

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

    cod (April 29th, 2014)

  4. #3
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    Default Re: Looping doesn't change value

    Thank you, yes it turns out that the if statements were outside the while loop hence only displaying the output is 0 but as for your first point about the 'while (data!=0)' statement, my code asks it to ADD the value to a variable and end the loop but considering that the value is 0 it shouldn't affect my loop. So I don't understand why that would make a difference in my code. Am I missing something? I don't understand why you would point that part of the code out. (I mean that in the most humble way possible, I'm very new to coding and just trying to learn, hope that inquiry didn't sound offensive.)
    Thank you so much for your help!
    Cheers

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    Default Re: Looping doesn't change value

    but as for your first point about the 'while (data!=0)' statement, my code asks it to ADD the value to a variable and end the loop but considering that the value is 0 it shouldn't affect my loop. So I don't understand why that would make a difference in my code. Am I missing something? I don't understand why you would point that part of the code out.
    What I'm pointing out is just to initialize your data variable to a number not equal to zero. Why? just to make sure that the while loop executes at least once. Actually you did it in your code, but you ask this question in your first post:
    Also i have a quick question, the program needs me to end the program when the value of data is 0 but in order to initialize it I need to give it a value. Usually I would give it a value of 0 like I have for rangesum and outrangesum but if I do the program does not run till the loop as it considers the value of data to be 0 and ends the program right away.
    or maybe I just did not understand what you are pointing out with that question that is why I ended up with a suggestion that made you confused. sorry, actually, I am not good in english.

  6. The Following User Says Thank You to dicdic For This Useful Post:

    cod (May 3rd, 2014)

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