fig05_26.cpp

《c＋＋大学教程》源码

// Fig. 5.26: fig05_26.cpp
// Demonstrating an array of pointers to functions.
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

// function prototypes
void function1( int );
void function2( int );
void function3( int );

int main()
{
   // initialize array of 3 pointers to functions that each 
   // take an int argument and return void
   void (*f[ 3 ])( int ) = { function1, function2, function3 };

   int choice;

   cout << "Enter a number between 0 and 2, 3 to end: ";
   cin >> choice;

   // process user's choice
   while ( choice >= 0 && choice < 3 ) {

      // invoke function at location choice in array f 
      // and pass choice as an argument
      (*f[ choice ])( choice ); 

      cout << "Enter a number between 0 and 2, 3 to end: ";
      cin >> choice;
   }

   cout << "Program execution completed." << endl;

   return 0;  // indicates successful termination

} // end main

void function1( int a )
{
   cout << "You entered " << a 
        << " so function1 was called\n\n";

} // end function1

void function2( int b )
{
   cout << "You entered " << b 
        << " so function2 was called\n\n";

} // end function2

void function3( int c )
{
   cout << "You entered " << c 
        << " so function3 was called\n\n";

} // end function3

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