Java类默认情况下，它将隐式扩展java.lang.Object [英] Java class by default, it will implicitly extend java.lang.Object

问题描述

在本教程中( http://www.studytonight.com/java/object -and-classes )我读到 java类可以选择扩展一个父类.默认情况下，它将扩展java.lang.Object.

In this tutorial (http://www.studytonight.com/java/object-and-classes) I read that a java class may optionally extend one parent class. By default, it will extend java.lang.Object.

注意:重要的声明是，我读到 Java枚举隐式扩展了java.lang.Enum类，因此您的枚举类型无法扩展另一个类.

Note: important statement that i was read that Java enums extend the java.lang.Enum class implicitly, so your enum types cannot extend another class.

请注意，我们普通的java类不应扩展enum之类的其他类(枚举类型不能扩展另一类).但是我们可以继承一个类.是多重继承吗?

according to note our normal java class should not extend other class like enum (enum types cannot extend another class).but we can able to inherit one class. is this multiple inheritance.?

可以通过extends关键字派生.像这样

in java class can derived by extends keyword. like this

class SomeClass
 { }
class MyClass extends SomeClass{}

默认情况下，所有Java类如何在Java中扩展Java.lang.Object类而不使用extends关键字?

How can all java classes by default extends java.lang.Object class without extends keyword in java?

当我们的班级扩展某些基类时，它将成为多重继承.我搜索了stackoverflow，但仍然不清楚. 默认情况下，任何类都可以扩展Object班级.并不是说Java支持多重继承吗?

When our class extends some base class, it becomes multiple inheritance. I searched in stackoverflow, but still I am not clear. By default any class extends Object class. Doesn't it mean java supports multiple inheritance?

任何人都可以通过简单示例对此进行澄清.

Can anybody clarify this with a simple example.

推荐答案

• 除java.lang.Object之外，每个类都只扩展一个类.
• 如果您编写extends Something，则您的课程会扩展Something.
• 如果您不编写extends Something，则您的类将扩展java.lang.Object. (就像您写extends Object一样)
• Every class, except for java.lang.Object, extends exactly one class.
• If you write extends Something, then your class extends Something.
• If you don't write extends Something, then your class extends java.lang.Object. (the same as if you wrote extends Object)

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