为什么我的Object数组的值在Java中仍然相同

我不明白为什么我的对象数组仍然保持不变。我试图从数组中计算索引。如何计算索引

public class TryArray {

    Students[] arr;

    public void add(Students std) {
        for (int i = 0; i < arr.length ; i++) {
            arr[i] = std;
         System.out.println(std); //it willbe more than one time displayed
            break;
        }
    }

    public TryArray(int lengthOfArray) { //Constructor for the length Array
        arr = new Students[lengthOfArray];
    }
}

预期产出：

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我错过什么了吗

您当前的代码中有很多错误的概念。首先，使用要添加的元素设置数组的所有元素。其次，在add方法中，打印变量乘以数组的长度，而不考虑正确的结果

您的TryArray类的代码可以这样重写：

public class TryArray {

    //array to store the students (elements)
    private Students[] arr;
    //counter of how many students are stored by this instance
    private int size;

    public void add(Students std) {
        /*
        the code here makes no sense, see explanation above
        for (int i = 0; i < arr.length ; i++) {
            arr[i] = std;
         System.out.println(std); //it willbe more than one time displayed
            break;
        }
        */
        if (size < arr.length) {
            arr[size++] = std;
            //this is for testing purposes only, in real life code
            //you shall avoid code like this here
            System.out.println(std);
        }
    }

    public TryArray(int lengthOfArray) { //Constructor for the length Array
        arr = new Students[lengthOfArray];
    }
}

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让我们看两件事：1学生课堂上的字段不能是静态的。2我们需要查看TryArrayadd的代码。我不确定索引的确切含义是什么，但在for循环中，您有一个中断；打印add中的第一个元素之后。因此，您只能看到[0]元素。在Students类中，它只是构造函数，其他什么都没有。这就是TryArrayadd@LuiggiMendozabut的代码，如果我不写break；我想显示我的数组**的对象，它将显示两次。我想显示**一次@KevinOIf，我把循环放在里面，如下所示：arr[I]=std，不间断；并使用System.out.println显示，它将被多次显示

1, Bob, Julius
2, Joe, Chris
3, Christian, Henderson

public class TryArray {

    //array to store the students (elements)
    private Students[] arr;
    //counter of how many students are stored by this instance
    private int size;

    public void add(Students std) {
        /*
        the code here makes no sense, see explanation above
        for (int i = 0; i < arr.length ; i++) {
            arr[i] = std;
         System.out.println(std); //it willbe more than one time displayed
            break;
        }
        */
        if (size < arr.length) {
            arr[size++] = std;
            //this is for testing purposes only, in real life code
            //you shall avoid code like this here
            System.out.println(std);
        }
    }

    public TryArray(int lengthOfArray) { //Constructor for the length Array
        arr = new Students[lengthOfArray];
    }
}