创建后更改数组大小 [英] Array size changing after creation

问题描述

任何人都可以解释这里发生的事情.我的印象是，数组的大小一旦创建并声明就无法更改.

can anyone explain whats happening here. I was under the impression that an array's size can't be changed once its been created and declared.

public class ArrayManipulation 
{
    public static void main(String[] args) 
    {
        int a[] = {1, 2, 3};//new int[3];
        int b[] = new int[a.length-1];

        System.out.print("a = ");
        for (int i = 0; i < a.length; i++)
            System.out.print(a[i] + "  ");
        System.out.println();

        for (int i = 0; i < b.length; i++)
            b[i] = a[i];
        //This is the bit I am confused about.. I was expecting an error here
        a = b;

        System.out.print("a = ");
        for (int i = 0; i < a.length; i++)
           System.out.print(a[i] + "  ");
        System.out.println();       
    }
}

推荐答案

数组是对象，是的，一旦创建，数组的大小就不会改变.

Arrays are objects, and yes, once they are created their size doesnt change.

a= b;

您将a引用指向b对象.因此，a所引用的初始对象仍在VM中，直到被垃圾回收为止.

you are pointing a reference to b object. So your initial object that a was referencing is still in VM until it s garbage collected.

但是您的数组大小没有变化，但是您引用的对象现在指向一个差异数组/对象

But your array size didnt change but you reference is pointing to a differet array/object now

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