使用数组查找 Java 中的最小值、最大值和平均值

Question

We are just starting to code in Java in our intro to programming class and I am hung up on where I've gone wrong with this particular assignment. The goal is to create a program that enters 15 test scores (values between 1 - 100) that are stored in an array. Then uses that array to compute the output for the minimum, maximum, and average score (average must be an accumulator).

Infinite loops with break statements are no allowed. Below is the code I have started along with notations from the professor.

We are running this code in Codiva and when I run it nothing populates. Not sure what all I am missing.

import java.util.Scanner;

class TestScoresCalulcated {
    public static void main(String[] args) {
        /**Declarations**/
        int index = 0;
        int index2 = 0;
        int min;
        int max;
        int testScore;
        int NUM_SCORES = 15;
        int[] listOfScores = new int[NUM_SCORES];

        Scanner in = new Scanner(System.in);

        for (index = 1; index <= NUM_SCORES; index++) {
            /**TODO:create a loop and make the variable index the loop control variable**/
            System.out.println("Enter in an integer:");
            testScore = in .nextInt();
        }

        min = 1;
        max = 100;

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (max < listOfScores[index2]) {
                max = listOfScores[index2];
            }
            System.out.println("Doing Max Calculation: " + max);
        }

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (min > listOfScores[index2]) {
                min = listOfScores[index2];
            }
            System.out.println("Doing Min Calculation: " + min);
        }

        //use the index2 as a loop variable as a index for the array. 
        /*TODO:create another loop
        //TODO:check if the element in the array less than max
          System.out.println("Doing max calulcation");
          //TODO: assign max variable
        //TODO:check if the element in the array less than min
          System.out.println("Doing min calculation");

        //consider doing accumulator calculation here to get the average.

    **/ //end of loop2

        //output the results here

    }
}

Answer 1

You are initializing index with value 0, then overwrite it with 1, so you are accessing your array starting with the second value. Also your loop ends using the length of the array as an index (15) which is actually the 16th element in your array that doesn't exist, you are definitely getting an error there.
You need to use < instead of <=

Also what @Nils said of not saving the values in the array at the first place.

Answer 2

We are just starting to code in Java in our intro to programming class and I am hung up on where I've gone wrong with this particular assignment. The goal is to create a program that enters 15 test scores (values between 1 - 100) that are stored in an array. Then uses that array to compute the output for the minimum, maximum, and average score (average must be an accumulator).

Infinite loops with break statements are no allowed. Below is the code I have started along with notations from the professor.

We are running this code in Codiva and when I run it nothing populates. Not sure what all I am missing.

import java.util.Scanner;

class TestScoresCalulcated {
    public static void main(String[] args) {
        /**Declarations**/
        int index = 0;
        int index2 = 0;
        int min;
        int max;
        int testScore;
        int NUM_SCORES = 15;
        int[] listOfScores = new int[NUM_SCORES];

        Scanner in = new Scanner(System.in);

        for (index = 1; index <= NUM_SCORES; index++) {
            /**TODO:create a loop and make the variable index the loop control variable**/
            System.out.println("Enter in an integer:");
            testScore = in .nextInt();
        }

        min = 1;
        max = 100;

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (max < listOfScores[index2]) {
                max = listOfScores[index2];
            }
            System.out.println("Doing Max Calculation: " + max);
        }

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (min > listOfScores[index2]) {
                min = listOfScores[index2];
            }
            System.out.println("Doing Min Calculation: " + min);
        }

        //use the index2 as a loop variable as a index for the array. 
        /*TODO:create another loop
        //TODO:check if the element in the array less than max
          System.out.println("Doing max calulcation");
          //TODO: assign max variable
        //TODO:check if the element in the array less than min
          System.out.println("Doing min calculation");

        //consider doing accumulator calculation here to get the average.

    **/ //end of loop2

        //output the results here

    }
}

Answer 3

We are just starting to code in Java in our intro to programming class and I am hung up on where I've gone wrong with this particular assignment. The goal is to create a program that enters 15 test scores (values between 1 - 100) that are stored in an array. Then uses that array to compute the output for the minimum, maximum, and average score (average must be an accumulator).

Infinite loops with break statements are no allowed. Below is the code I have started along with notations from the professor.

We are running this code in Codiva and when I run it nothing populates. Not sure what all I am missing.

import java.util.Scanner;

class TestScoresCalulcated {
    public static void main(String[] args) {
        /**Declarations**/
        int index = 0;
        int index2 = 0;
        int min;
        int max;
        int testScore;
        int NUM_SCORES = 15;
        int[] listOfScores = new int[NUM_SCORES];

        Scanner in = new Scanner(System.in);

        for (index = 1; index <= NUM_SCORES; index++) {
            /**TODO:create a loop and make the variable index the loop control variable**/
            System.out.println("Enter in an integer:");
            testScore = in .nextInt();
        }

        min = 1;
        max = 100;

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (max < listOfScores[index2]) {
                max = listOfScores[index2];
            }
            System.out.println("Doing Max Calculation: " + max);
        }

        for (index2 = 1; index2 <= NUM_SCORES; index2++) {
            if (min > listOfScores[index2]) {
                min = listOfScores[index2];
            }
            System.out.println("Doing Min Calculation: " + min);
        }

        //use the index2 as a loop variable as a index for the array. 
        /*TODO:create another loop
        //TODO:check if the element in the array less than max
          System.out.println("Doing max calulcation");
          //TODO: assign max variable
        //TODO:check if the element in the array less than min
          System.out.println("Doing min calculation");

        //consider doing accumulator calculation here to get the average.

    **/ //end of loop2

        //output the results here

    }
}

Answer 4

Actually you don't need an array to accomplish this assignment.

I prepared a to do list to solve your assignment.

1. In the first loop you have to fill your array (if you really need an array), but your code just assign entered value to testScore variable.

2. It is a good programming practice that checking user entries. What if user enters a string value.

3. You can find min and max values in the first loop. Hint: initialize min = 100; max = 1;

4. To find average, accumulate entered values in a variable like total.

5. Outside of the loop, find average value dividing total with NUM_SCORES .

In case you need I send my solution:

import java.util.InputMismatchException;
import java.util.Scanner;

class TestScoresCalulcated {
    public static void main(String[] args) {
        /** Declarations **/
        int min = 100;
        int max = 1;
        int total = 0;
        int testScore;
        int NUM_SCORES = 15;


        Scanner in = new Scanner(System.in);

        for (int i = 0; i < NUM_SCORES;) {
            try {
                System.out.println("Enter " + (i + 1) + ". value: ");
                testScore = in.nextInt();

                if (testScore < 1 || testScore > 100) {
                    throw new IllegalArgumentException();
                }

                if (testScore < min) {
                    min = testScore;
                }

                if (testScore > max) {
                    max = testScore;
                }

                total += testScore;
                ++i;

            } catch (InputMismatchException | IllegalArgumentException e) {
                System.out.println("Please enter numbers between 1 and 100\n");
                in.nextLine();
            }

        }

        System.out.println("\nOutput:");
        System.out.println("Min: " + min);
        System.out.println("Max: " + max);
        System.out.println("Average: " + total / NUM_SCORES);

        in.close();
    }
}