Answer:
- Can an object reference variable exist that without referring to an object?
- Yes, a reference variable can be declared without
initialization:
String myString; - Also, a reference can be
set to
null.
- Yes, a reference variable can be declared without
initialization:
- Can an object exist without an object reference variable that refers to it?
- Yes, as seen in the previous example. Such objects are temporary.
The startsWith() Method
Here is another method of the String class:
public boolean startsWith(String prefix);
The startsWith() method tests if one
String is the prefix of another.
This is frequently needed in programs.
(Although this example is too short to show a real-world situation,
study it carefully.)
class PrefixTest
{
public static void main ( String args[] )
{
String burns = "My love is like a red, red rose.";
if ( burns.startsWith( "My love" ) )
System.out.println( "Prefix 1 matches." );
else
System.out.println( "Prefix 1 fails." );
if ( burns.startsWith( "my love" ) )
System.out.println( "Prefix 2 matches." );
else
System.out.println( "Prefix 2 fails." );
if ( burns.startsWith( " My love" ) )
System.out.println( "Prefix 3 matches." );
else
System.out.println( "Prefix 3 fails." );
if ( burns.startsWith( " My love".trim() ) )
System.out.println( "Prefix 4 matches." );
else
System.out.println( "Prefix 4 fails." );
}
}
Notice how trim() is used in the last if statement.
QUESTION 24:
What does the program write to the monitor?