12. std::string

• A string is an STL container designed to accommodate sequence of characters, that is, text.

• Strings provide built-in features to operate on fragments of text and individual characters.

• The design is more intuitive than zero-terminated character arrays, commonly known as C-strings.

  
      #include <cassert>
      #include <string>
      using namespace std;
      int main (int argc, char* argv[])
      {
          string str( "Hello" );
          for ( int idx = 0; idx < str.length(); ++idx ) {
              // Access and modify individual characters:
              str[ idx ] = toupper( str[ idx ] );
          }
          assert( str == "HELLO" );
  
          str.append( 3, '!' ); // add three exclamation points
          assert( str == "HELLO!!!" );
  
          int pos1 = str.find( "L" );  //    HELLO!!!
          int pos2 = str.rfind( "L" ); //      ||
          assert( pos1 == 2 );         // pos1-''-pos2
          assert( pos2 == 3 );
  
          // Get 2-character long substring starting at pos1:
          assert( str.substr( pos1, 2 ) == "LL" );
  
          str.replace( pos1, 3, "YDAY" ); // HE...!!!
          assert( str == "HEYDAY!!!" );   //   '-----pos1
          return 0;
      }
  
  

• For more information, see CIS-62 std::string coverage.