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Thread: Why do I get this error?

  1. #1
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    Default Why do I get this error?

    Hello,

    I posted this program last night and got help with the sorting of the arrays, but I still get an error whenever I try and run it. There is something wrong with the input portion of my code in the main and I'm not sure what it is.

    The program is to prompt the user for the number of students, the student names, and their scores. It should then print them out in decreasing order of their scores.

    Output should be:

    Enter number of students: 3
    Smith 70
    Jones 30
    Peterson 100

    The print out is
    Jones 30
    Smith 70
    Peterson 100


    However, my output / print out is coming out as:

    Enter number of Students: 3 Smith 70 Jones 30 Mary 100
    Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:909)
    at java.util.Scanner.next(Scanner.java:1530)
    at java.util.Scanner.nextInt(Scanner.java:2160)
    at java.util.Scanner.nextInt(Scanner.java:2119)
    at Exercise06_19.main(Exercise06_19.java:18)
    Java Result: 1

     
    import java.util.Scanner;
     
    public class Exercise06_19 {
     
        public static void main(String[] args) {
            Scanner input = new Scanner(System.in);
     
            System.out.print("Enter number of Students: ");
            int numberOfStudents = input.nextInt();
     
            String[] name = new String[numberOfStudents];
            for (int i = 0; i < name.length; i++) {
                name[i] = input.next();
            }
            int[] score = new int[numberOfStudents];
            for (int i = 0; i < score.length; i++) {
                score[i] = input.nextInt();
            }
            decreasingOrder(name, score);
        }
     
        public static void decreasingOrder(String[] name, int[] score) {
     
            for (int i = 0; i < score.length; i++) {
                if (score[i] < score[i + 1]) {
                    int swap = score[i];
                    String swap2 = name[i];
                    score[i] = score[i + 1];
                    score[i + 1] = swap;
                    name[i] = name[i + 1];
                    name[i + 1] = swap2;
                }
                System.out.println(name[i] + score[i]);
            }
        }
    }

    Any kind of help/guidance would be great Thanks!


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Why do I get this error?

    InputMismatchException
    The nextInt() method called on line 18 is reading a non-numeric String. It wants all numeric digits it can convert to an int.
    What did you type in?
    What order of input does your program expect? numeric vs non-numeric
    What did you give it?

  3. #3
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    Default Re: Why do I get this error?

    Hey thanks for replying

    I typed in : 3 Smith 70 Jones 30 Mary 100

    The order entered should be numberOfStudents name[0] score[0] name[1] score[1] name[2] score[2]

    I'm giving it an integer, string, integer, string, integer, string, integer.

    Am I not able to do this? I was trying to make it so the String for loop grabs just the names and the Integer for loop grabs the scores, but keep them together, so name[0] = Smith and score[0] = 70

  4. #4
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    Default Re: Why do I get this error?

    If you want to read all names and then all scores then your input will have to be in the same order as you attempt to read it. Surely that makes sense. How is the computer supposed to read your mind and skip the score entries and only read the name entries?
    Improving the world one idiot at a time!

  5. #5
    Think of me.... Mr.777's Avatar
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    Default Re: Why do I get this error?

    Quote Originally Posted by Bryan29 View Post
    Hey thanks for replying

    I typed in : 3 Smith 70 Jones 30 Mary 100

    The order entered should be numberOfStudents name[0] score[0] name[1] score[1] name[2] score[2]

    I'm giving it an integer, string, integer, string, integer, string, integer.

    Am I not able to do this? I was trying to make it so the String for loop grabs just the names and the Integer for loop grabs the scores, but keep them together, so name[0] = Smith and score[0] = 70
    Enter Name: ABC (name[0])
    Enter Name: DEF (name[1])
    ...
    ...
    ...
    Enter Marks: 12 (score[0])
    Enter Marks: 75 (score[1])
    ...
    ...
    ABC=12
    DEF=75

    What else do you want it to do?