我有一个简单的问题，我似乎找不到答案。我认为这真的很简单，我可以把它当作语言怪癖。
int[] newArray=new int[5];
将初始化一个数组并在所有 5 个位置上都为零。
newArray[4]=0;
//versus not assigning any value to specific position newArray[4]
两个是一样的吗？如果不是，如何区分这两者？
如何区分创建数组时自动放置的零与程序中某个时刻分配的零？
我问这个的主要原因是我有一个程序，它在数组中的随机位置分配一些整数值，也可以是 0。在搜索时，我想知道程序分配了哪些零，哪些是初始化的零。
Since you put ints in your array they are equivalent because the default value of int is 0. You won't be able to differentiate the two because 0 equals 0.
If you use Integer however the array will be initialized with nulls. In that case you can tell whether a value was set or not.
If you want to be able to tell the difference you can use references.
int[] newArray=new int[5] will initialize all elements to 0 by default.
newArray[4]=0 will set the value of 5th element to 0. All other's will be by default anyways. So there's no difference between the two.
To understand this set newArray[4]=10 instead.
Now the array content is {0,0,0,0,10}
Why do you say quirk? It's clear that every reference and primitive has an initial default value in Java. For int it's 0. For references it's null.
如果将变量实例化为类的成员，它将具有默认值：数字为 0，对象为 null。但是，如果您在方法中声明该变量，编译器不会为该变量分配默认值，因此在您设置它之前，它的内容是未定义的。
因此，如果您在方法中执行此操作，则不等效；-)