What will s2 contain after following lines of Java code?

 StringBuffer s1 = "one";
StringBuffer s2 = s1.append("two")

In Java, which class is used to represent a sequence of characters as a string?

A. String

B. StringBuilder

C. StringSequence

D. StringArray

What is the correct way to create a new empty String object in Java?

A. String emptyString = "";

B. String emptyString = new String();

C. String emptyString = " ";

D. String emptyString = null;

E. Both A and B

In Java, which operator is used to concatenate two strings?

A. +

B. &

C. ,

D. |

Which of the following methods is used to compare two strings for equality in Java?

A. equals()

B. compareTo()

C. equalsIgnoreCase()

D. compare()