java语言extends用法是什么？

在Java中，通过关键字返闭extends继承一个已有的类，被继承的类称为父类(超类，基类)，新的类隐型称为子类(派生类)。在Java中不允许多继承。漏携裂\x0d\x0a举例：\x0d\x0a\x0d\x0aclass Animal{ \x0d\x0a void eat(){ \x0d\x0a System.out.println("Animal eat") \x0d\x0a } \x0d\x0a void sleep(){ \x0d\x0a System.out.println("Animal sleep") \x0d\x0a } \x0d\x0a void breathe(){ \x0d\x0a System.out.println("Animal breathe") \x0d\x0a } \x0d\x0a} \x0d\x0a \x0d\x0aclass Fish extends Animal{ \x0d\x0a void breathe(){ \x0d\x0a System.out.println("Fish breathe") \x0d\x0a } \x0d\x0a} \x0d\x0a \x0d\x0apublic class TestNew { \x0d\x0a public static void main(String[] args) { \x0d\x0a Animal an = new Animal() \x0d\x0aFish fn = new Fish() \x0d\x0aan.breathe() \x0d\x0afn.breathe() \x0d\x0a\x0d\x0a } \x0d\x0a} \x0d\x0a执行结果：\x0d\x0aAnimal breathe\x0d\x0aFish breathe

在Java中猛握陆，通过关键字extends继承一个已有的类，被继承的类称为父类(超类，基类)，新的类称为子类(派生类)。在Java中不允许多继承。枝顷

举例：

class

Animal{

void

eat(){

System.out.println("Animal

eat")

}

void

sleep(){

System.out.println("Animal

sleep")

}

void

breathe(){

System.out.println("Animal

breathe")

}

}

class

Fish

extends

Animal{

void

breathe(){

System.out.println("Fish

breathe")

}

}

public

class

TestNew

{

public

static

void

main(String[]

args)

{

Animal

an

=

new

Animal()

Fish

fn

=

new

Fish()

an.breathe()

fn.breathe()

}

}

执行结果：皮蚂

Animal

breathe

Fish

breathe

---