为什么我无法使用关键字“this”当引用静态方法中的字段？ [英] Why can't I use the keyword "this" when referring to fields in static methods?

问题描述

public class Date
{

static int month; 

public static void setMonth(int x)
{ 
 this.month = x;  //compiler error
}

public static int getMonth()
{
 return month;  //compiles just fine, no error
}

}

当编译时，我收到错误：非静态变量这不能从静态上下文引用。
但是，如果我删除this。没有错误。
我不明白为什么当我使用关键字static清楚地声明它是一个非静态变量。

When compiling, I receive the error: non-static variable this cannot be referenced from a static context. However, if I remove "this." there is no error. I don't understand why it's saying month is a non-static variable when I clearly declared it using the keyword static.

推荐答案

你不能在静态上下文中使用 this 。这是通过设计 - 这指的是对象而不是类。如果您在方法参数和字段之间可能发生名称冲突，您可以改用类名称：

You simply can't use this in a static context. That is by design - this refers to the object not the class. If you are having problems with possible name clashes between method parameters and fields you can use the class name instead:

public static void setMonth(int month)
{ 
 Date.month = month; 
}

另一方面，您可以考虑您的设计并重新思考使用整个类作为一个单例对象。

On the other hand you could think about your design and rethink the decision to use the whole class as one singleton object.

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