13-Application of inheritance

/*1. The use of inheritance 1> when two classes have the same properties and methods, you can extract the same things into a parent class 2> when Class A fully owns some of the properties and methods in class B, consider having class B inherit a Class A {    int _age;    int _no; }  b:a {    int _weight;}  Inheritance: xx is xxx//combination: XXX has xxx  2. Combination A {     int _age;     int _no; }  B {     A *_a;     int _weight; }*/@interface score:nsobject{    int _cscore;    int _ocscore;} @end @implementation score@end@interface student:nsobject{    //Combo/************* Format * * * * * Uppercase class name *_ lowercase class name; ************* /    score *_score;//    int _cscore;//    int _ocscore;    int _age;} @end @implementation Student@end

　　

13-Application of inheritance