stringcompare.java

用JAVA编写的字符的比较

public class StringCompare 
{
   public static void main( String args[] )
   {
      String s1 = new String( "hello" ); // s1 is a copy of "hello"
      String s2 = "goodbye";
      String s3 = "Happy Birthday";
      String s4 = "happy birthday";

      System.out.printf( 
         "s1 = %s\ns2 = %s\ns3 = %s\ns4 = %s\n\n", s1, s2, s3, s4 );

      // test for equality
      if ( s1.equals( "hello" ) )  // true
         System.out.println( "s1 equals \"hello\"" );
      else
         System.out.println( "s1 does not equal \"hello\"" ); 

      // test for equality with ==
      if ( s1 == "hello" )  // false; they are not the same object
         System.out.println( "s1 is the same object as \"hello\"" );
      else
         System.out.println( "s1 is not the same object as \"hello\"" );

      // test for equality (ignore case)
      if ( s3.equalsIgnoreCase( s4 ) )  // true
         System.out.printf( "%s equals %s with case ignored\n", s3, s4 );
      else
         System.out.println( "s3 does not equal s4" );

      // test compareTo
      System.out.printf( 
         "\ns1.compareTo( s2 ) is %d", s1.compareTo( s2 ) );
      System.out.printf( 
         "\ns2.compareTo( s1 ) is %d", s2.compareTo( s1 ) );
      System.out.printf( 
         "\ns1.compareTo( s1 ) is %d", s1.compareTo( s1 ) );
      System.out.printf(
         "\ns3.compareTo( s4 ) is %d", s3.compareTo( s4 ) );
      System.out.printf(
         "\ns4.compareTo( s3 ) is %d\n\n", s4.compareTo( s3 ) );

      // test regionMatches (case sensitive)
      if ( s3.regionMatches( 0, s4, 0, 5 ) )
         System.out.println( "First 5 characters of s3 and s4 match" );
      else
         System.out.println( 
            "First 5 characters of s3 and s4 do not match" );

      // test regionMatches (ignore case)
      if ( s3.regionMatches( true, 0, s4, 0, 5 ) )
         System.out.println( "First 5 characters of s3 and s4 match" );
      else
         System.out.println( 
            "First 5 characters of s3 and s4 do not match" );
   } // end main
} // end class StringCompare