chap20.lst

Borland C++ Builder The Complete Reference 例程源代码

listing 1
#include <iostream> 
using namespace std; 
 
int main() 
{ 
  int i; 
  char str[80]; 
 
  cout << "I like C++ Builder.\n";  // this is a single-line comment 
  /* you can still use C-style comments, too */ 
 
  // input a number using >> 
  cout << "Enter a number: "; 
  cin >> i; 
 
  // now, output a number using << 
  cout << "Your number is " << i << "\n"; 
 
  // read a string 
  cout << "Enter a string: "; 
  cin >> str; 
  // print it 
  cout << str; 
 
  return 0; 
}

listing 2
#include <stdio.h>

listing 4
// This creates the class queue. 
class queue { 
  int q[100]; 
  int sloc, rloc; 
public: 
  void init(); 
  void qput(int i); 
  int qget(); 
};

listing 5
#include <iostream> 
using namespace std; 
 
// This creates the class queue. 
class queue { 
  int q[100]; 
  int sloc, rloc; 
public: 
  void init(); 
  void qput(int i); 
  int qget(); 
}; 
 
void queue::init() 
{ 
  rloc = sloc = 0; 
} 
 
void queue::qput(int i) 
{ 
  if(sloc==99) { 
    cout << "Queue is full.\n"; 
    return; 
  } 
  sloc++; 
  q[sloc] = i; 
} 
 
int queue::qget() 
{ 
  if(rloc == sloc) { 
    cout << "Queue underflow.\n"; 
    return 0; 
  } 
  rloc++; 
  return q[rloc]; 
} 
 
int main() 
{ 
  queue a, b;  // create two queue objects 
 
  // now, access the queues through their member functions 
  a.init(); 
  b.init(); 
 
  a.qput(10); 
  b.qput(19); 
 
  a.qput(20); 
  b.qput(1); 
 
  cout << a.qget() << " "; 
  cout << a.qget() << " "; 
  cout << b.qget() << " "; 
  cout << b.qget() << "\n"; 
 
  return 0; 
}

listing 6
#include <iostream> 
using namespace std; 
 
// sqr_it is overloaded three ways 
int sqr_it(int i); 
double sqr_it(double d); 
long sqr_it(long l); 
 
int main() 
{ 
  cout << sqr_it(10) << "\n"; 
  cout << sqr_it(11.0) << "\n"; 
  cout << sqr_it(9L) << "\n"; 
 
  return 0; 
} 
 
// Define sqr_it for ints. 
int sqr_it(int i) 
{ 
  cout << "Inside the sqr_it() function that uses "; 
  cout << "an integer argument.\n"; 
 
  return i*i; 
} 
 
// Overload sqr_it for doubles. 
double sqr_it(double d) 
{ 
  cout << "Inside the sqr_it() function that uses "; 
  cout << "a double argument.\n"; 
 
  return d*d; 
} 
 
// Overload sqr_it again, this time for longs. 
long sqr_it(long l) 
{ 
  cout << "Inside the sqr_it() function that uses "; 
  cout << "a long argument.\n"; 
 
  return l*l; 
}

listing 7
#include <iostream> 
using namespace std; 
 
void prompt(char *str, int *i); 
void prompt(char *str, double *d); 
void prompt(char *str, long *l); 
 
int main() 
{ 
  int i; 
  double d; 
  long l; 
 
  prompt("Enter an integer: ", &i); 
  prompt("Enter a double: ", &d); 
  prompt("Enter a long: ", &l); 
 
  cout << i << " " << d << " " << l; 
 
  return 0; 
} 
 
// Prompt for an int. 
void prompt(char *str, int *i) 
{ 
  cout << str; 
  cin >> *i; 
} 
 
// Prompt for a double. 
void prompt(char *str, double *d) 
{ 
  cout << str; 
  cin >> *d; 
} 
 
// Prompt for a long. 
void prompt(char *str, long *l) 
{ 
  cout << str; 
  cin >> *l; 
}

listing 8
class road_vehicle { 
  int wheels; 
  int passengers; 
public: 
  void set_wheels(int num); 
  int get_wheels(); 
  void set_pass(int num); 
  int get_pass(); 
};

listing 9
class truck : public road_vehicle { 
  int cargo; 
public: 
  void set_cargo(int size); 
  int get_cargo(); 
  void show(); 
};

listing 10
#include <iostream> 
using namespace std; 
 
class road_vehicle { 
  int wheels; 
  int passengers; 
public: 
  void set_wheels(int num); 
  int get_wheels(); 
  void set_pass(int num); 
  int get_pass(); 
}; 
 
// Extend road_vehicle for trucks. 
class truck : public road_vehicle { 
  int cargo; 
public: 
  void set_cargo(int size); 
  int get_cargo(); 
  void show(); 
}; 
 
enum type {car, van, wagon}; 
 
// Extend road_vehicle for cars. 
class automobile : public road_vehicle { 
  enum type car_type; 
public: 
  void set_type(enum type t); 
  enum type get_type(); 
  void show(); 
}; 
 
void road_vehicle::set_wheels(int num) 
{ 
  wheels = num; 
} 
 
int road_vehicle::get_wheels() 
{ 
  return wheels; 
} 
 
void road_vehicle::set_pass(int num) 
{ 
  passengers = num; 
} 
 
int road_vehicle::get_pass() 
{ 
  return passengers; 
} 
 
void truck::set_cargo(int num) 
{ 
  cargo = num; 
} 
 
int truck::get_cargo() 
{ 
  return cargo; 
} 
 
void truck::show() 
{ 
  cout << "Wheels: " << get_wheels() << "\n"; 
  cout << "Passengers: " << get_pass() << "\n"; 
  cout << "Cargo capacity in cubic feet: " << cargo << "\n"; 
} 
 
void automobile::set_type(enum type t) 
{ 
  car_type = t; 
} 
 
enum type automobile::get_type() 
{ 
  return car_type; 
} 
 
void automobile::show() 
{ 
  cout << "Wheels: " << get_wheels() << "\n"; 
  cout << "Passengers: " << get_pass() << "\n"; 
  cout << "Type: "; 
  switch(get_type()) { 
    case van: cout << "Van\n"; 
      break; 
    case car: cout << "Car\n"; 
      break; 
    case wagon: cout << "Wagon\n"; 
  } 
} 
 
int main() 
{ 
  truck t1, t2; 
  automobile c; 
 
  t1.set_wheels(18); 
  t1.set_pass(2); 
  t1.set_cargo(3200); 
 
  t2.set_wheels(6); 
  t2.set_pass(3); 
  t2.set_cargo(1200); 
 
  t1.show(); 
  t2.show(); 
 
  c.set_wheels(4); 
  c.set_pass(6); 
  c.set_type(van); 
  c.show(); 
 
  return 0; 
}

listing 11
// This creates the class queue. 
class queue { 
  int q[100]; 
  int sloc, rloc; 
public: 
  queue();  // constructor 
  ~queue(); // destructor 
  void qput(int i); 
  int qget(); 
}; 
 
// This is the constructor function. 
queue::queue() 
{ 
  sloc = rloc = 0; 
  cout << "Queue initialized.\n"; 
} 
 
// This is the destructor function. 
queue::~queue() 
{ 
  cout << "Queue destroyed.\n"; 
}

listing 12
#include <iostream> 
using namespace std; 
 
// This creates the class queue. 
class queue { 
  int q[100]; 
  int sloc, rloc; 
public: 
  queue();  // constructor 
  ~queue(); // destructor 
  void qput(int i); 
  int qget(); 
}; 
 
// This is the constructor function. 
queue::queue() 
{ 
  sloc = rloc = 0; 
  cout << "Queue initialized.\n"; 
} 
 
// This is the destructor function. 
queue::~queue() 
{ 
  cout << "Queue destroyed.\n"; 
} 
 
void queue::qput(int i) 
{ 
  if(sloc==99) { 
    cout << "Queue is full.\n"; 
    return; 
  } 
  sloc++; 
  q[sloc] = i; 
} 
 
int queue::qget() 
{ 
  if(rloc == sloc) { 
    cout << "Queue underflow.\n"; 
    return 0; 
  } 
  rloc++; 
  return q[rloc]; 
} 
 
int main() 
{ 
  queue a, b;  // create two queue objects 
 
  a.qput(10); 
  b.qput(19); 
 
  a.qput(20); 
  b.qput(1); 
 
  cout << a.qget() << " "; 
  cout << a.qget() << " "; 
  cout << b.qget() << " "; 
  cout << b.qget() << "\n"; 
 
  return 0; 
}