Swapping strings

Class string provides member function swap for swapping strings. Figure 18.4 swaps two strings.

Figure 18.4. Using function swap to swap two strings.

1 // Fig. 18.4: Fig18_04.cpp 2 // Using the swap function to swap two strings. 3 #include 4 using std::cout; 5 using std::endl; 6 7 #include 8 using std::string; 9 10 int main() 11 { 12 string first( "one" ); 13 string second( "two" ); 14 15 // output strings 16 cout << "Before swap: first: " << first << " second: " << second; 17 18 first.swap( second ); // swap strings 19 20 cout << " After swap: first: " << first 21 << " second: " << second << endl; 22 return 0; 23 } // end main  

Before swap: first: one second: two After swap: first: two second: one  

Lines 1213 declare and initialize strings first and second. Each string is then output. Line 18 uses string member function swap to swap the values of first and second. The two strings are printed again to confirm that they were indeed swapped. The string member function swap is useful for implementing programs that sort strings.

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