Java 数组排序及表格输出教程

import java.util.Scanner;

public class ArrayIntro2 {

    public static void main(String[] args) {
        // integer array
        int[] TestGrades = new int[25];

        // creating object of ArrayIntro2T
        ArrayIntro2T pass = new ArrayIntro2T(TestGrades, 0, 0, 0);

        // getting total and filling array
        int scoreCount = ArrayIntro2T.FillArray(TestGrades, 0);

        // get average score
        double avg = pass.ComputeAverage(TestGrades, scoreCount);

        // outputting unsorted table
        System.out.println("Original Test Scores:");
        ArrayIntro2T.OutputArray(TestGrades, scoreCount, avg);

        // Sort and output sorted table
        System.out.println("\nTable of sorted test scores");
        ArrayIntro2T.OutputSortedArray(TestGrades, scoreCount, avg);

    }

}

// new class to store methods
class ArrayIntro2T {
    // variable declaration

    double CalcAvg = 0;
    int ScoreTotal = 0;
    int ScoreCount = 0;
    int[] TestGrades = new int[25];

    // constructor
    public ArrayIntro2T(int[] TestGradesT, int ScoreCountT, double CalcAvgT, int ScoreTotalT) {
        TestGrades = TestGradesT;
        ScoreCount = ScoreCountT;
        CalcAvg = CalcAvgT;
        ScoreTotal = ScoreTotalT;

    }

    // method to fill array
    public static int FillArray(int[] TestGrades, int ScoreCount) {

        Scanner scan = new Scanner(System.in);

        System.out.println("Please enter test scores one at a time, up to 25 values or enter -1 to quit");
        TestGrades[ScoreCount] = scan.nextInt();

        if (TestGrades[ScoreCount] == -1) {
            System.out.println("You have chosen to quit ");
        }

        while (TestGrades[ScoreCount] >= 0 && ScoreCount < TestGrades.length -1) {
            ScoreCount++;
            System.out.println("Enter the next test score or -1 to finish ");
            TestGrades[ScoreCount] = scan.nextInt();
            if (TestGrades[ScoreCount] == -1) {
                break;
            }
        }
        return ScoreCount;

    }

    // method to compute average
    public double ComputeAverage(int[] TestGrades, int ScoreCount) {

        for (int i = 0; i < ScoreCount; i++) {
            ScoreTotal += TestGrades[i];
            CalcAvg = (double) ScoreTotal / (double) ScoreCount;
        }

        return CalcAvg;

    }

    public static void selectionSort(int[] arr, int[] indices, int length) {
        for (int i = 0; i < length - 1; i++) {
            int minIndex = i;
            for (int j = i + 1; j < length; j++) {
                if (arr[indices[j]] < arr[indices[minIndex]]) {
                    minIndex = j;
                }
            }
            // Swap indices
            int temp = indices[i];
            indices[i] = indices[minIndex];
            indices[minIndex] = temp;
        }
    }

    // method to output scores and average
    public static void OutputArray(int[] TestGrades, int ScoreCount, double CalcAvg) {

        System.out.println("Grade Number\t\tGrade Value");

        for (int i = 0; i < ScoreCount; i++) {
            System.out.println((i + 1) + "\t" + "\t" + "\t" + TestGrades[i]);
        }

        System.out.printf("Calculated Average\t" + "%.2f%%\n", CalcAvg);

    }

    public static void OutputSortedArray(int[] TestGrades, int ScoreCount, double CalcAvg) {
        int[] indices = new int[TestGrades.length];
        for (int i = 0; i < TestGrades.length; i++) {
            indices[i] = i;
        }

        selectionSort(TestGrades, indices, ScoreCount);

        System.out.println("Grade Number\t\tGrade Value");

        for (int i = 0; i < ScoreCount; i++) {
            System.out.println((indices[i] + 1) + "\t" + "\t" + "\t" + TestGrades[indices[i]]);
        }

        System.out.printf("Calculated Average\t" + "%.2f%%\n", CalcAvg);
    }

}