It counts the number of characters in that String
.
class StringDemo1
{
public static void main ( String[] args )
{
String str ;
str = new String( "Elementary, my dear Watson!" );
}
}
The new
operator asks for an object to be constructed.
The Java virtual computer creates an object by following
the description contained in its class.
The example program creates a String
object.
When the program runs, the expression
new String( "Elementary, my dear Watson!" )
creates a new String
object
by following the description contained in the String
class.
This description is contained in a standard software package that comes with Java.
The particular object created in this case
contains characters "Elementary, my dear Watson!".
The new object contains all the methods and features
that are described in the String
class.
All objects of the same class contain the same methods.
All objects of the same class contain the same types of data
although the values of the data will be different from object to object.
For example, all String
objects contain the same methods.
All String
objects contain a string of characters,
but the characters will be different from object to object.
The program could now use the methods of this object to do some things with the characters. However, this program does nothing further. After the program stops running, the object no longer exists. The memory out of which it was made can now be used for other purposes.
Mentally change the program so that it creates a
String
object containing the characters
"You know my methods, Watson."