I cannot return a value from my array

Question

This is assessed work so please don't give a straight answer.

My program is supposed to calculate the users grade: "pass" , "fail" or "pass with compensation". However, it doesn't return the answer. I'm unable to figure out why - can anyone help?

public class MarkCalculator { static int[] marks = new int[12];

//public static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args) {
    Scanner kb = new Scanner(System.in);
    int weighting;
    int coursework;
    int exammark;

    System.out.println("Please enter course work weighting");
    marks[0]= kb.nextInt();

    System.out.println("Please enter course work mark");
    marks[1]= kb.nextInt();

    System.out.println("Please enter exam mark");
    marks[2]= kb.nextInt();


    MarkCalculator mc = new MarkCalculator();
    mc.computeMarks(marks);

}




public String[] computeMarks(int[] marks) {

    final int[] WEIGHTING = {55,66,55,44,33,44};
    String[] results = new String[WEIGHTING.length];
    for (int i = 0; i < marks.length / 2; i++) {

        int exam = marks[i];
        int cw = marks[i];
        int weight = WEIGHTING[i];
        int formula = ((cw + weight) + (exam * (100 - weight)) / 100);

        if (formula >= 40){
            results[i]="PASS";
        } else if ((formula < 39) && (formula > 35)){
            results[i]="COMPENSATION PASS";
        }else{
            results[i]="FAIL";

        }

    }

    return results;
}

}

Just a side note, when formula==39 result will be FAIL, I don't think this is what you are expecting — Roman-Stop RU aggression in UA
– Roman-Stop RU aggression in UA, Commented Nov 6, 2013 at 16:38

Paul Samsotha · Accepted Answer · 2013-11-06 16:36:26Z

3

final int[] WEIGHTING = {};
String[] results = new String[WEIGHTING.length];

Here's a problem. WEIGHTING has no initial size.

answered Nov 6, 2013 at 16:36

Paul Samsotha

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6 Comments

Kojotak Over a year ago

Yes, you can declare variable as final in method.

user2961364 Over a year ago

I had numbers initialized in weighting but took them out just playing around with it to hopefully find a solution

user2961364 Over a year ago

I had six random numbers, but i shouldn't have to initialize numbers because say if someones weighting was outside the 6 numbers?

Paul Samsotha Over a year ago

@user2961364, then you would need a an ArrayList or a some kind of List. Arrays don't auto-increment.

Paul Samsotha Over a year ago

keep in mind also, you haven't given an values to marks in your code above.

|

wxyz · Accepted Answer · 2013-11-06 16:53:58Z

1

Also: you don't initialize marks with anything. Try this:

System.out.println("Please enter course work weighting");
        marks[0]= kb.nextInt();

        System.out.println("Please enter course work mark");
        marks[1]= kb.nextInt();

        System.out.println("Please enter exam mark");
        marks[2]= kb.nextInt();

        MarkCalculator mc = new MarkCalculator();
        mc.computeMarks(marks);

edited Nov 6, 2013 at 16:53

answered Nov 6, 2013 at 16:38

wxyz

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6 Comments

user2961364 Over a year ago

hey by mark[0], mark[1] and mark[2]. Do you mean marks[0],marks[1] and marks[2] because mark isn't defined?

user2961364 Over a year ago

so i've changed ---- final int[] WEIGHTING = {55,66,55,44,33,44}; ---so WEIGHTING now has some numbers as the weighting of the cw.

user2961364 Over a year ago

but for the markCalculator bit i don't really understand, it doesn't allow me to put numbers inside it to pass marks.

user2961364 Over a year ago

but when i input mark amounts and weighting the program still terminates without any calculation which it should complete

wxyz Over a year ago

do you print your results somewhere like System.out.println(mc.computeMarks(marks).toString());?

|

Ankit Rustagi · Accepted Answer · 2013-11-06 17:31:44Z

1

The problem is WEIGHTING is empty

final int[] WEIGHTING = {}; // empty
String[] results = new String[WEIGHTING.length];
for (int i = 0; i < marks.length / 2; i++) {

    int exam = marks[i];
    int cw = marks[i];
    int weight = WEIGHTING[i]; // You cant access elements from an empty array

Also

    MarkCalculator mc = new MarkCalculator();
    mc.computeMarks(marks);

here you are passing marks which is empty.

EDIT

Reason why your program wasnt working is because you are not catching the result from computeMarks. You should store it in an array inside main like

String[] result = mc.computeMarks(marks);

for(int k=0;k<result.length;k++)
{
    System.out.println(result[k]);
}

edited Nov 6, 2013 at 17:31

answered Nov 6, 2013 at 16:39

Ankit Rustagi

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2 Comments

user2961364 Over a year ago

I've set weighting as final int[] WEIGHTING = {55,66,55,44,33,44};

user2961364 Over a year ago

and marks[0]= kb.nextInt(); marks[1]= kb.nextInt(); marks[2]= kb.nextInt(); so marks isn't empty anymore? still not receiving answer informing me whether it's pass ect

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