java String StringBuffer

What does the following print?

System.out.println( "And yet, it moves!".charAt(0) );

• A

• n

• !

• The statement is incorrect.

What does the following print?

String str = "And yet, it moves!"

System.out.println( str.charAt( str.length() ) );

• A

• n

• !

• The statment is incorrect.

Examine the following fragment:

String cat = "Hello"

cat += " ";

cat += "World" ;

How many objects are constructed?

• 0

• 1

• 2

• 3

Examine the following fragment:

String world = "World!";

StringBuffer buf = new StringBuffer( "Hello" );

buf.append(' ');

buf.append( world );

How many StringBuffer objects are constructed?

• 0

• 1

• 2

• 3

Which phrase best describes a String object after it has been constructed?

• Changeable

• Write Only

• Read Only

• Inaccessible

Which character of a StringBuffer has index 0?

• leftmost

• rightmost

• no character

After a StringBuffer has been constructed, how many characters may be added to it?

• No more after it has been constructed.

• Only as many as the original capacity.

• As many as needed; it will grow in size if necessary.

• A new StringBuffer must be constructed each time characters are added.

What is the potential number of characters in a StringBuffer called?

• length

• size

• width

• capacity

What is the current number number of characters in a StringBuffer called?

• length

• size

• width

• capacity

You wish to compare the contents of two StringBuffer objects. How should this be done?

• Use the == operator.

• Use the equals() method of StringBuffer.

• Construct a String object from each StringBuffer and use their equals() method.

• Do a character-by-character comparison using charAt() and ==.