继承:
关键字:extends
格式:
类A extends 类B
类A为父类 类B为子类
功用:
让类之间产生关系===》》多态
提高代码的复用性
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
注意:
切勿滥用继承,必须有所属关系
简单代码举例:
1 class C 2 { 3 void demo1(){} 4 } 5 6 class B extends C 7 { 8 void demo2(){} 9 //void demo1(){} B和A不必作此声明 10 } 11 12 class A extends C 13 { 14 //void demo1(){} 15 void demo3(){} 16 }