blocks|key|2657404|text|因为字段不支持多态性。MyClass.k是9+(MyClass指的是object+)。SampleThree.k会给你90的。每个类都有自己的一组变量。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2657405|2657406|entityMap^0|B|9|L|1|O|7|Y|6|17|D|1N|2|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@$9|J|A|K|B|C]|$9|L|A|M|B|C]|$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]|$1|G|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|H|$]]

Because fields do not support polymorphism. <code>MyClass.k</code> is <code>9</code> (and <code>object</code> is of refered to by <code>MyClass</code>). <code>SampleThree.k</code> would give you <code>90</code>. Each class has its own set of variables.

(Btw, An IDE would give you a warning here that you are accessing a static variable by an instance, rather than by its class.)

blocks|key|2665406|text|因为继承的目的是修改行为。行为是通过方法公开的，这些方法可以被重写。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2665407|你可以做的是重载一个字段，而不是重写。为此，您需要在接口外部定义该变量，以便为它们提供不同的值。|2665408|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Because inheritance is intended to modify behaviour. Behaviour is exposed through methods and those methods can be overridden .

What you can do is to overload a field , not override . 
For that you need to define that variable outside the Interface in order to give them different values .

blocks|key|2657411|text|在接口MyInterface中有一个静态变量k。你已经在MyClass类中实现了这个接口，那么MyClass.k应该是9。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2657412|对象由MyClass引用。SampleThree.k会给你90分|2657413|或者简单地说：|2657414|不能重写|2657415|静态变量。|blockquote|2657416|2657417|2657418|覆盖静态和实例变量&方法的规则：|2657419|2657420|如果实例方法重写静态方法，则会发生编译错误。|ordered-list-item|2657421|如果静态方法隐藏了实例方法，则会发生编译错误。|2657422|允许静态变量隐藏实例variable.|2657423|It's也允许实例变量隐藏静态变量。|2657424|2657425|entityMap^0|3|B|M|1|S|7|1B|9|0|3|7|D|D|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1E|8|@$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1J|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|1K|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1L|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|1N|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1O|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|1P|8|@]|D|@]|E|$]]|$1|T|3|U|5|V|7|1Q|8|@]|D|@]|E|$]]|$1|W|3|X|5|V|7|1R|8|@]|D|@]|E|$]]|$1|Y|3|Z|5|V|7|1S|8|@]|D|@]|E|$]]|$1|10|3|11|5|V|7|1T|8|@]|D|@]|E|$]]|$1|12|3|-4|5|6|7|1U|8|@]|D|@]|E|$]]|$1|13|3|-4|5|6|7|1V|8|@]|D|@]|E|$]]]|14|$]]

You have a static variable <code>k</code> in interface <code>MyInterface</code>. You have implement this interface in class <code>MyClass</code>, then <code>MyClass.k</code> should be 9.

Object is refered to by <code>MyClass</code>. <code>SampleThree.k</code> would give you 90.

Or simply:

<blockquote>
 Static variable can not be override.
</blockquote>

Rules for Overriding static and instance variable &amp; methods:

<ol>
<li>A compilation error occurs if an instance method overrides a static method.</li>
<li>A compilation error occurs if a static method hides an instance method.</li>
<li>It's permissible for a static variable to hide an instance variable.</li>
<li>It's also permissible for an instance variable to hide a static variable. </li>
</ol>

blocks|key|753102|text|覆盖概念不适用于变量(因此覆盖规则)。该值始终基于引用类型，而不是基于运行时对象。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|753103|这就是为什么你的程序打印9，因为对象的引用类型是MyClass，而MyClass继承了值为9的k。无论static修饰符(K)是什么，行为都是一样的。.If你在MyClass中取消注释行，输出总是89。|offset|length|style|CODE|BOLD|753104|entityMap^0|0|O|7|X|7|28|7|1F|6|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@$D|M|E|N|F|G]|$D|O|E|P|F|G]|$D|Q|E|R|F|G]|$D|S|E|T|F|H]]|9|@]|A|$]]|$1|I|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|J|$]]

Overriding concept is not applicable to variables(hence overriding rules). The value is always based on reference type but not based on the run time object.

That's why your program is printing 9 because the reference type of object is <code>MyClass</code>, and <code>MyClass</code> inherited k whose value is 9.The behavior is same irrespective of the static modifier(k ).If you uncomment the line in <code>MyClass</code> the output is always 89.

blocks|key|2657439|text|您正在创建MyClass的引用变量。因此，如果使用这个变量，你将访问k，那么它将显示接口的变量。如果要访问值为90变量，请引用SampleThree类的变量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2657440|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

You are creating Reference Variable of MyClass. So if using this variable you will access k then it will show variable of interface. If you want to access variable having value 90 make reference variable of SampleThree class.

<pre><code>package com.mycompany.myproject.mypkg;

interface MyInterface {
 public static final int k = 9;
}

class MyClass implements MyInterface {
 // int k = 89;
}

public class SampleThree extends MyClass {
 static int k = 90;

 public static void main(String args[]) {
 MyClass object = new SampleThree();
 System.out.println(object.k);
 }
}
</code></pre>

Why does the above program print '9' instead of '90'?

How are static and member variables overridden in Java?

How are variables overridden

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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package com.mycompany.myproject.mypkg;interface MyInterface {    public static final int k = 9;}class MyClass implements MyInterface {    // int k = 89;}public class SampleThree extends MyClass {    s

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