To answer this question, let's analyze each line of code and the corresponding output.
Integer ten = new Integer(10);
- This line creates an
Integer
object named ten
with a value of 10.
Long nine = new Long(9);
- This line creates a
Long
object named nine
with a value of 9.
System.out.println(ten + nine);
- In this line, the
+
operator is used to concatenate ten
and nine
.
- When using the
+
operator with objects, the toString()
method is called on each object, and the resulting strings are concatenated.
- The
toString()
method for Integer
and Long
classes converts the objects to their corresponding string representations.
- Therefore, the output of this line will be "19" (10 + 9).
int i = 1;
- This line creates an
int
variable named i
with a value of 1.
System.out.println(i + ten);
- In this line, the
+
operator is used to add i
and ten
.
- Since
ten
is an Integer
object, it will be unboxed to its corresponding int
value before the addition.
- Therefore, the expression will be evaluated as
1 + 10
, resulting in the output "11".
Based on the above analysis, the correct answer is:
A. 19 followed by 20