Java - 为什么将 "null"分配给变量不会使其可用于 GC？ (在此代码段中)

Question

我正在阅读 oracle 提供的在线教程。其中一个练习题如下:

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The following code creates one array and one string object. How many references to those objects exist after the code executes? Is either object eligible for garbage collection?

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String[] students = new String[10];
String studentName = "Peter Smith";
students[0] = studentName;
studentName = null;
...

Answer: There is one reference to the students array and that array has one reference to the string Peter Smith. Neither object is eligible for garbage collection.

( http://docs.oracle.com/javase/tutorial/java/javaOO/QandE/objects-answers.html )

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最后一行肯定意味着 studentName 有资格获得 GC 吗？真的很困惑，我认为这意味着我没有理解“null”的本质以及正确的对象引用，这就是我问的原因。

Answer 1

在将 null 分配给 studentName 之前，有两个对“Peter Smith”的引用(studentName 和 students[0])。在将 null 分配给 studentName 后，“Peter Smith”仍被 students[0]

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