Java编程中的参考变量 [英] reference variables in java programming

问题描述

大家好，

可以告诉我在Java中的void引用变量中声明ref变量吗?

C#

hi everyone,

Can tell me declare ref variable in void reference variable in java?

c#

void x(ref int o)
{
  o++;
}

如何使用Java?

感谢您的帮助.

How in java?

Thanks for any help

推荐答案

Java中的参数始终按值传递.在函数中传递的基元(如样本中的整数)在内部进行了修改，但实际参数的传递值在返回后似乎没有被修改.在您的示例中，您需要返回o作为返回值.

因为(类的)对象是引用对象，所以按值传递它们意味着它们的引用按值传递，因此对象本身的行为就像在C ++中按引用传递一样.如果将此类对象传递给Java函数并在此处进行修改，则返回后，该对象将显示为已修改.

我知道一篇很好的文章很好地解释了这一切: http://www.yoda.arachsys.com/java/passing. html [ ^ ].

—SA

Parameters in Java are always passed by value. Primitives (like integer in your sample) passed in the function are modified inside, but passed value of actual parameter appears not modified after return. In your example, you need to return o as a return value.

As object (of classes) are reference object, passing them by value means their references are passed by value, so the object itself behaves like if it is passed by reference in C++. If you pass such object to Java function and modify it there, after return it appears modified.

I know excellent article explaining all that very well: http://www.yoda.arachsys.com/java/passing.html[^].

—SA

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