If you want to change an immutable object, you don't - you create a new object with the changed value and point your reference to it.

如果您想要改变一个不可变对象的话，您不会改变它，而是使用修改后的值来创建一个新的对象，并把您的引用指向它。

youdao

In addition, these simple built-in types are immutable, which means you can't change an object's value after the object has been created.

另外，这些简单的内置类型是不可改变的，这意味着：创建对象之后，您无法更改对象的值。

youdao

If the USN value sent does not match the USN value currently persisted in the repository, the ce server knows that a change was made (by some other caller) since the object was fetched.

如果发送的US n值与储存库中储存的值不匹配，CE服务器就知道已经(由其他调用方)进行了更新，因此该对象已被获取。

youdao