在所有面向对象的编程语言中，继承都是很重要的内容，是面向对象最基本的应用，可以使程序更加优化，便于编写。希望大家掌握这一基本内容。-All object-oriented programming languages, inheritance is very important content, is the basic object-oriented application, you can make the program more optimized, easy to write. I ho