fig18_01.cpp

是有关C++编程原理教程的例子程序,全,应该对大家有所帮助

// Fig. 18.1: Fig18_01.cpp
// Demonstrating string assignment and concatenation.
#include <iostream>
using std::cout;
using std::endl;

#include <string>
using std::string;

int main()
{
   string string1( "cat" );
   string string2;
   string string3;

   string2 = string1; // assign string1 to string2
   string3.assign( string1 ); // assign string1 to string3
   cout << "string1: " << string1 << "\nstring2: " << string2
      << "\nstring3: " << string3 << "\n\n";

   // modify string2 and string3 
   string2[ 0 ] = string3[ 2 ] = 'r';

   cout << "After modification of string2 and string3:\n" << "string1: " 
      << string1 << "\nstring2: " << string2 << "\nstring3: ";

   // demonstrating member function at
   for ( int i = 0; i < string3.length(); i++ ) 
      cout << string3.at( i );

   // declare string4 and string5
   string string4( string1 + "apult" ); // concatenation
   string string5;

   // overloaded +=                               
   string3 += "pet"; // create "carpet"           
   string1.append( "acomb" ); // create "catacomb"

   // append subscript locations 4 through end of string1 to
   // create string "comb" (string5 was initially empty)
   string5.append( string1, 4, string1.length() - 4 );
                                 
   cout << "\n\nAfter concatenation:\nstring1: " << string1 
      << "\nstring2: " << string2 << "\nstring3: " << string3 
      << "\nstring4: " << string4 << "\nstring5: " << string5 << endl;
   return 0;
}  // end main

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