setofcharacters.java

程序练习中包括书中实例程序代码和练习中要用到的代码,是压缩文件

package questions.c6;
public class SetOfCharacters {
   private String chars = "";
   public void addChar( char c ) {
      chars += c;
   }
   public boolean contains( char c ) {
      // indexOf will return -1 if the character
      // is not present
      return ( chars.indexOf( c ) >= 0 );
   }
   public static void main( String[] args ) {
      SetOfCharacters soc = new SetOfCharacters();
      soc.addChar( 'j' );
      soc.addChar( 'p' );
      System.out.println( "Set contains 'j': "
                          + soc.contains( 'j' ) );
      System.out.println( "Set contains 'k': "
                          + soc.contains( 'k' ) );
   }
}