OBJECT-ORIENTED THINKING - Introduction to Java Programming: Comprehensive Version - page 392

4 public void Test(String s) {
5 text = s;
6 }
7
8 public static void main(String[] args) {
9 Test test = new Test( "ABC" );
10 System.out.println(test);
11 }
12 }

10.24

Show the output of the following code.

public class Test {
public static void main(String[] args) {
System.out.println( "Hi, ABC, good" .matches( "ABC " ));
System.out.println( "Hi, ABC, good" .matches( ".*ABC.*" ));
System.out.println( "A,B;C" .replaceAll( ",;" , "#" ));
System.out.println( "A,B;C" .replaceAll( "[,;]" , "#" ));

String[] tokens = "A,B;C" .split( "[,;]" );
for ( int i = 0 ; i < tokens.length; i++)
System.out.print(tokens[i] + " " );
}
}

10.25

Show the output of the following code.

public class Test {
public static void main(String[] args) {
String s = "Hi, Good Morning" ;
System.out.println(m(s));
}

public static int m(String s) {
int count = 0 ;
for ( int i = 0 ; i < s.length(); i++)
if (Character.isUpperCase(s.charAt(i)))
count++;

return count;

}
}

10.11 The StringBuilder and StringBuffer Classes
The StringBuilder and StringBuffer classes are similar to the String class
except that the String class is immutable.

Key
Point

In general, the StringBuilder and StringBuffer classes can be used wherever a string
is used. StringBuilder and StringBuffer are more flexible than String . You can add,
insert, or append new contents into StringBuilder and StringBuffer objects, whereas
the value of a String object is fixed once the string is created.
The StringBuilder class is similar to StringBuffer except that the methods for mod-
ifying the buffer in StringBuffer are synchronized , which means that only one task is
allowed to execute the methods. Use StringBuffer if the class might be accessed by multi-
ple tasks concurrently, because synchronization is needed in this case to prevent corruptions to

StringBuilder