Thread: Comparing Elements in Array to find the Highest Int

So in this program, which is a grading program, I am trying to compare all the students averages to find who has the highest one and list the grades and the student's names from least to greatest. Yes, I see there are other problems in the program but it is nowhere near finished.

 
 
import java.util.Scanner;
 
public class Main {
	public static void main(String[] args) {
		String[] studentName = new String[20];
		int[] studentAverage = new int[20];
		Scanner input = new Scanner(System.in);
		int numberOf = 0;
		int sub = 0;
		int x = 0;
		int[] answers;
		int[] correct;
		int whichStudent = 0;
		int timesRan = 0;
		String AvToOr, letterGrade, stuNameAsk, goOn;
		while (x == 0) {
			whichStudent = sub;
 
			System.out
					.println("Enter student name. (Current limit of amount of students is 20.)");
			stuNameAsk = input.next();
			studentName[sub] = stuNameAsk;
 
			System.out
					.println("How many questions would you like to ask? (Maximum is infinite.)");
			int num = input.nextInt(); // get the number of times to ask
			answers = new int[num]; // student's answers
			correct = new int[num]; // for teachers
			for (int x1 = 0; x1 < num; x1++) {
				System.out.println("Enter the answer for question number: "
						+ (x1 + 1) + ".");
				correct[x1] = input.nextInt();
			}
			System.out.println("Now for the students.");
			for (int x1 = 0; x1 < num; x1++) {
				System.out
						.println("Enter the student answer for question number:"
								+ (x1 + 1));
				answers[x1] = input.nextInt();
			}
			int average = 0; // his/her grade
			for (int x1 = 0; x1 < num; x1++)
				if (correct[x1] == answers[x1])
					average++;
 
			average = (int) (((double) average) / ((double) num) * 100);
			if (average >= 90 && average <= 100) {
				letterGrade = "A";
 
			} else if (average >= 80 && average <= 89) {
				letterGrade = "B";
			} else if (average >= 70 && average <= 79) {
				letterGrade = "C";
			} else if (average >= 60 && average <= 69) {
				letterGrade = "D";
			} else {
				letterGrade = "F";
			}
			studentAverage[sub] = average;
			System.out.println(studentName[0 + whichStudent] + "'s grade is "
					+ studentAverage[0 + whichStudent] + "%");
			System.out
					.println("Do you want to enter another student? Type Y for yes and N for no.");
			goOn = input.next();
 
			if (goOn.equalsIgnoreCase("n")) {
				x++;
 
			} else if (goOn.equalsIgnoreCase("y")) {
				sub++;
				timesRan++;
 
			} else {
				System.out
						.println("Your answer is not valid. Please try again.");
				System.out.println("Do you want to enter another student?");
				goOn = input.next();
 
				if (goOn.equalsIgnoreCase("n")) {
					x++;
 
				} else if (goOn.equalsIgnoreCase("y")) {
					sub++;
					timesRan++;
 
				} else {
					System.out
							.println("Your answer is not valid. Program restarted.");
				}
			}
		}
		System.out.println("All entered students and their averages:");
		for (int varTest = 0; varTest <= timesRan; varTest++) {
			System.out.println(studentName[varTest] + "'s average is "
					+ studentAverage[varTest] + "%");
		}

Here is the specific place in which I'm trying to put the grades in order from highest to lowest...

		System.out
				.println("Would you like to (A)verage, put in (or)der from highest grade to lowest grade, or (end) the program? (Case does not matter)");
		AvToOr = input.next();
 
		 if	 (AvToOr.equalsIgnoreCase("A")){
			for (int varTest = 0; varTest <= timesRan; varTest++){
				//System.out.println(studentAverage[varTest] + studentAverage[varTest-1]);
			}
 
			}
		 else if (AvToOr.equalsIgnoreCase("top")){
				System.out.println("Test");
		}
		 else if (AvToOr.equalsIgnoreCase("or")){
			 System.out.println("test");
		 }
		 else if (AvToOr.equalsIgnoreCase("end")){
 
		 }
 
	}
}

Thanks

Do you have a question?

Originally Posted by Cornix

Do you have a question?

I am trying to compare all the students averages to find who has the highest one and list the grades and the student's names from least to greatest. I need help with this.

Originally Posted by Norm

Ok.
Can you explain where you are having problems? Maybe ask a specific question that some one can help you with.

I don't know what i would have to do to compare multiple array elements against each other.

Have you ever discussed a sorting algorithm in class? Because they are quite similar to this problem, perhaps you might re-use some of the thoughts from the sorting algorithm.
If not, then think how you would do it by hand, on a piece of paper perhaps.
Write down a list of possible entries and then think, step by step, how you would find the highest value from those entries by hand.

Originally Posted by Cornix

Have you ever discussed a sorting algorithm in class? Because they are quite similar to this problem, perhaps you might re-use some of the thoughts from the sorting algorithm.
If not, then think how you would do it by hand, on a piece of paper perhaps.
Write down a list of possible entries and then think, step by step, how you would find the highest value from those entries by hand.

Thanks for the help! This is the code I wrote to do it....

for (int index = 0; index <= timesRan; index++)
			{
				if (studentAverage[index] > highest)
				highest = studentAverage[index];
 
 
			}
			for(int tester = 0; tester <= timesRan; tester++){
				if (studentAverage[tester]==highest){
					topStudent = studentName[tester];
					tester = timesRan++;
				}
				else {
 
				}
			}
			System.out.println(highest +"%"+ " was the highest grade by " + topStudent);
		} else if (AvToOr.equalsIgnoreCase("end")) {
 
		}

Do you have any more questions or problems?