Strings, Characters and Regular Expressions - Java: How to Program Early Objects - page 608

last character to copy (i.e., copy up to, but not including , that index in the String ). The
substring returned contains a copy of the specified characters from the original String . An
index outside the bounds of the String causes a StringIndexOutOfBoundsException .

14.3.6 Concatenating Strings
String method concat (Fig. 14.7) concatenates two String objects (similar to using the +
operator) and returns a new String object containing the characters from both original
String s. The expression s1.concat(s2) at line 13 forms a String by appending the char-
acters in s2 to the those in s1 . The original String s to which s1 and s2 refer are not modified .

1 // Fig. 14.7: StringConcatenation.java

2 // String method concat.

3
4 public class StringConcatenation

5 {

6 public static void main(String[] args)

7 {

8 String s1 = "Happy " ;

9 String s2 = "Birthday" ;

10
11 System.out.printf( "s1 = %s%ns2 = %s%n%n" ,s1, s2);

12

System.out.printf(

13

"Result of s1.concat(s2) = %s%n" , s1.concat(s2) );

14

System.out.printf( "s1 after concatenation = %s%n" , s1);

15

}

16

} // end class StringConcatenation

s1 = Happy
s2 = Birthday

Result of s1.concat(s2) = Happy Birthday
s1 after concatenation = Happy

Fig. 14.7 | String method concat .

14.3.7 Miscellaneous String Methods
Class String provides several methods that return String s or character arrays containing
copies of an original String 's contents which are then modified. These methods—none
of which modify the String on which they're called—are demonstrated in Fig. 14.8.

1

// Fig. 14.8: StringMiscellaneous2.java

2

// String methods replace, toLowerCase, toUpperCase, trim and toCharArray.

3
4

public class StringMiscellaneous2

5

{

6

public static void main(String[] args)

7

{

Fig. 14.8 | String methods replace , toLowerCase , toUpperCase , trim and toCharArray .
(Part 1 of 2.)