Java保存对象引用是如何工作的? [英] How does Java saving object reference work?

问题描述

 String a = "test";字符串 b = a;a = "wuut";System.out.println(b);

打印出test

难道b 不应该持有a 的引用，而不是仅仅取其值?

Java 不是这样处理对象和东西的吗?

解决方案

当 a 被创建时，可以说它指向将 memory_1 放在内存中.

当 b 分配给 a 时，b 也指向相同的 memory_1 位置.>

现在，当 a 更改值时(并且因为 String 对象是不可变的)，现在会在内存中创建一个新值，现在 a 指向 memory_2.

但是嘿，b 仍然指向 memory_1.

PS:不变性是:

<块引用>

在面向对象和函数式编程中，不可变对象是指在创建后状态无法修改的对象.

    String a = "test";
    String b = a;

    a = "wuut";

    System.out.println(b);

Prints out test

Shouldn't b hold refence of a, not just take its value?

Doesn't Java work that way with objects and stuff?

解决方案

When a is created lets say it point to place memory_1 in memory.

When b is assigned to a, then b also points to the same memory_1 location.

Now, when a changes value (and because the String Object is immutable) a new value is created now in memory and now a points in memory_2.

But hey, b still points in memory_1.

PS: Immutability is:

In object-oriented and functional programming, an immutable object is an object whose state cannot be modified after it is created.

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