Parameter list Call Subclass constructor

sometimes, the base class constructor is with parameters, and the subclass constructor is without parameters, as follows:classanimal{ Public: Animal (intWidthintHeight) { This->width = width; This->height =height;}Private:    intwidth, height;};classCat: Publicanimal{ Public: Cat () {cout<<"Init cat"<<Endl;}}; Compile error when building Cat class object: C:\Documents and settings\administrator\ desktop \abc\text1.cpp (104): Error C2512:'Animal': no appropriatedefaultconstructor available solve this problem you should explicitly call the parameter constructor of the base class in the cat's constructor. Because the parameter constructor is defined in the base class, the compiler does not provide a default constructor. (or you can add a constructor without parameters to the base class) This problem will be resolved. Here's how to call the base class with a parameter constructor:classCat: Publicanimal{ Public: Cat (): Animal ( -, $) {cout <<"Init cat"<<Endl;} The argument list calls the subclass constructor usage}; That is, add a colon after the constructor, followed by the constructor of the base class. This method can also be used to initialize constants in a class. Constants are not allowed because members are not allowed to be initialized in the class definition. As shown below:classCat: Publicanimal{ Public: Cat (): Animal ( -, $), Age (2), Islikefish (true) {cout <<"Init cat"<<Endl;}Private:    Const intAge ; Const BOOLislikefish;};

Parameter list Call Subclass constructor