# 类的继承与构造函数

* 如果基类有默认构造函数，派生类缺省，那么会自动有一个默认构造函数
* 如果基类没有默认构造函数，即只有带参数的构造函数，派生类缺省，应该会报错
* 如果基类既有默认构造函数，又有带参数的构造函数，派生类缺省，自动默认构造函数
* 想用带参数的构造函数，一定要手动
* C++11新增特性：using BaseClass::BaseClass;


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