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java - 我正在尝试创建一个将显示有关一组整数的信息的类，但我无法调用我的类

问题描述

好的，我试图理解你的答案并更改了我的代码，但我仍然遇到类似的问题。我正在尝试将IntArray构造函数调用到我的IntMath构造函数中，因为我需要一些变量才能使我的数学工作。之后，我试图将两个构造函数都调用到我的 Main 类中。然而，它告诉我，我所有的变量“可能都没有被初始化。我对此很陌生，只是感到愚蠢和无助。我已经疯狂地使用谷歌了。提前感谢你的帮助。

package com.company;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        //int sum, even, odd, min, max, size;
        //int [] intArray;
        //double average;
        //int even = 0, odd = 0, min = 0, max = 0, size = 0, sum = 0;
        //double average;
        System.out.print("Please enter a number for the array size (zero or greater):  ");
        int n=in.nextInt();
        if (n<0){
            System.out.println("ERROR: Number must be at least zero!!!");
        }else {
            IntArray mainArray = new IntArray(n);
        }
        //com.company.IntMath intMath = new com.company.IntMath(average, even, odd, min, max, size, sum);
        IntMath intMath = new IntMath();
        //intMath.getAverage();
        intMath.getEven();
        intMath.getOdd();
        intMath.getMin();
       // intMath.getMax();
        intMath.getSize();
        intMath.getSum();

        System.out.println("Average: " + intMath.getAverage() );  //print the average of the elements
        System.out.println("Even Count: " + intMath.getEven()); //prints the count of all even numbers
        System.out.println("Odd Count: " + intMath.getOdd()); //prints the count of all odd numbers
        System.out.println("Min: " + intMath.getMin()); //prints the min number
        //System.out.println("Max: " + intMath.getMax()); //prints the max number
        System.out.println("Size: " + intMath.getSize()); //prints the size of the array
        System.out.println("Sum: " + intMath.getSum()); //prints the sum of all elements

    }
}

package com.company;

import java.util.Arrays;
import java.util.Random;

public class IntArray {
    private int n;
    private int [] intArray;
    private double average;
    private int sum;
    private int even;
    private int odd;
    private int max;
    private int min;
    private int size;

    public IntArray(int n) {
        this.n = n;

        Random randArray = new Random();
        int[] intArray = new int[n];
        intArray[0] = 0; //why does this not make the element 0 a 0?????????
        for (int i = 0; i < n; i++) {
            intArray[i] = randArray.nextInt(50); //I was getting very big random numbers, so I set the max to 50
        }
        System.out.println("Set: " + Arrays.toString(intArray));


    }
    public double getAverage() {
        average = 0;
        double total = 0;
        for (int i = 0; i < n; i++) {
            total = total + intArray[i];
        }
        return average;
    }

    public int getSum() {
        //find the sum of all elements
        sum = 0;
        for (int i = 0; i < n; i++) {
            sum += intArray[i];
        }
        return sum;
    }

    public int getEven() {
        even = 0;
        for (int i = 0; i < n; i++) {
            if (intArray[i] % 2 == 0) {
                even++;
            }
        }
        return even;
    }

    public int getOdd() {
        odd = 0;
        for (int i = 0; i < n; i++) {
            if (intArray[i] % 2 != 0) {
                odd++;
            }
        }
        return odd;
    }

    public int getMax() {
        max = intArray[0];
        for (int i = 1; i < n; i++) {
            if (intArray[i] > max) {
                max = intArray[i];
            }
        }
        return max;
    }

    public int getMin() {
        min = 0;
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < intArray.length; j++) {
                if (intArray[i] > intArray[j]) {
                    min = intArray[i];
                    intArray[i] = intArray[j];
                    intArray[j] = min;
                }
            }
        }
        return min;
    }

    public int getSize() {

        //find the size of the array
        size = n + 1;
        return size;
    }

}

package com.company;
public class IntMath {
    private double average;
    private int sum;
    private int even;
    private int odd;
    private int max;
    private int min;
    private int size;
    private int[] intArray;
    private int n;

    //com.company.IntArray mainArray = new com.company.IntArray(n); //call IntArray to get variables ''n'' and ''intArray''


    /*public IntMath(double average, int sum, int even, int odd, int max, int min, int size, int[] intArray) {
        this.average = average;
        this.sum = sum;
        this.even = even;
        this.odd = odd;
        this.max = max;
        this.min = min;
        this.size = size;
        this.intArray = intArray;

        com.company.IntArray mainArray = new com.company.IntArray(n); //call IntArray to get variables ''n'' and ''intArray''

        // average = 0;
        // double total = 0;
        // for (int i = 0; i < n; i++) {
        //     total = total + intArray[i];
        // }


        //find the sum of all elements
        //sum = 0;
        //for (int i = 0; i < n; i++) {
        //    sum += intArray[i];
        //}

        //find the count of the even numbers
        //even = 0;
        //for (int i = 0; i < n; i++) {
        //    if (intArray[i] % 2 == 0) {
        //        even++;
        //    }
        //}

        //find the count of the odd numbers
        //odd = 0;
        //for (int i = 0; i < n; i++) {
        //    if (intArray[i] % 2 != 0) {
        //        odd++;
        //    }
        //}

        //find the biggest number
        //max = intArray[0];
        //for (int i = 1; i < n; i++) {
        //    if (intArray[i] > max) {
        //        max = intArray[i];
        //    }
        //}

        //find the smallest number
        //min = 0;
        //for (int i = 0; i < n; i++) {
        //    for (int j = i + 1; j < intArray.length; j++) {
        //        if (intArray[i] > intArray[j]) {
        //            min = intArray[i];
        //            intArray[i] = intArray[j];
        //            intArray[j] = min;
        //        }
        //    }
    /

    //find the size of the array
    //size = n + 1;
*/

    public double getAverage() {
        average = 0;
        double total = 0;
        for (int i = 0; i < n; i++) {
            total = total + intArray[i];
        }
        return average;
    }

    public int getSum() {
        //find the sum of all elements
        sum = 0;
        for (int i = 0; i < n; i++) {
           sum += intArray[i];
        }
        return sum;
    }

    public int getEven() {
        even = 0;
        for (int i = 0; i < n; i++) {
            if (intArray[i] % 2 == 0) {
                even++;
            }
        }
        return even;
    }

    public int getOdd() {
        odd = 0;
        for (int i = 0; i < n; i++) {
            if (intArray[i] % 2 != 0) {
                odd++;
            }
        }
        return odd;
    }

    public int getMax() {
        max = intArray[0];
        for (int i = 1; i < n; i++) {
            if (intArray[i] > max) {
                max = intArray[i];
            }
        }
        return max;
    }

    public int getMin() {
        min = 0;
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < intArray.length; j++) {
                if (intArray[i] > intArray[j]) {
                    min = intArray[i];
                    intArray[i] = intArray[j];
                    intArray[j] = min;
                }
            }
        }
        return min;
    }

    public int getSize() {

        //find the size of the array
        size = n + 1;
        return size;
    }
}

标签： java

解决方案

在 Main 类中，如果您初始化所有变量，则该类将编译而不会出错。

通过学习你的课程，我想你可能想做的是，

  • 接受一个数字以创建该大小的数组并用一些随机数填充数组
  • 接下来，您要使用已填充的数组执行各种操作，例如求平均值、求和等。

如果是这种情况，那么你将不得不做这样的事情......

  • 实际上，您不需要 IntArray 类。
  • 将 int[] intArray 声明为 IntMath 类中的类级别变量，并像现在一样在 IntArray 类的构造函数中填充该数组。
  • 在 IntMath 类中为每个操作定义多个方法..average、sum 等，并在打印答案时在 Main 类中调用它们。
  • 您必须更正 getAverage、getSize 和 getMin 方法中的代码。

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