C++ for the MFE class at UC Berkeley课件.ppt

Accessing Class Members Frisky.Weight = 50; Frisky.Meow(); Cat Frisky; // just like int x; Frisky.age = 5; // just like x = 5; If You Don’t Declare It, Your Class Wont Have It Cat Frisky; // make a Cat named Frisky Frisky.Bark() // tell Frisky to bark 精品文档 Sample program #2 1: // Demonstrates declaration of a class and 2: // definition of an object of the class, 3: 4: #include iostream.h // for cout 5: 6: class Cat // declare the class object 7: { 8: public: // members which follow are public 9: int itsAge; 10: int itsWeight; 11: }; 12: 13: 14: void main() 15: { 16: Cat Frisky; 17: Frisky.itsAge = 5; // assign to the member variable 18: cout Frisky is a cat who is ; 19: cout Frisky.itsAge years old.\n; 20: } Output: Frisky is a cat who is 5 years old. 精品文档 Implementing Class Methods void Cat::Meow() { cout Meow.\n; } Calling class function void main() { Cat Frisky; Frisky.Meow(); } 精品文档 Using internal variables inside class void main() { Cat Frisky; Cat Whisky; Frisky.itsAge = 3; Whisky.itsAge = 5; cout Frisky says: ; Frisky.Meow(); cout Whisky says: ; Whisky.Meow(); } Frisky says: Meow Meow Meow Whisky says: Meow Meow Meow Meow Meow class Cat { public: int itsAge; int itsWeight; void Meow(); } void Cat::Meow() // the older the cat, the more noisy it is... { for ( int I = 0 ; I itsAge ; I++ ) cout Meow ; cout \n; } 精品文档 Public / Private class Cat { public: int GetAge(); void SetAge(int age); void HappyBirthday(); private: int itsAge; }; int Cat::GetAge() { return itsAge; } void Cat::SetAge(int age) { itsAge = age; } void main() { Cat Frisky; Frisky.SetAge(5); cout Frisky is a cat who is ; cout Frisky.GetAge() years old.\n; Frisky.HappyBirthday(); cout Frisky