QUESTION $1$

When using wrapper classes, it is always necessary to explicity covert between the wrapper class and the corresponding primitive data type.

True

False

$6$ points

QUESTION $2$

Before we can use a JOptionPane, it is necessary to instantiate an object of that class.

True

False

$6$ points

QUESTION $3$

It is not necessary to use an import statement when using the JOptionPane class in our code.

True

False

$6$ points

QUESTION $4$

The showMessageDialog static method of the JOptionPane class will create a pop$-$up that will prompt a user for input.

True

False

$6$ points

QUESTION $5$

Which of the following $($choose all correct answers$)$ are wrapper classes?

String

int

Byte

DrDre

Boolean

Integer

double

$16$ points

QUESTION $6$

What $($if anything$)$ is the value of the variabl num$1$ after the execution of the following code:

Double d$1=$ new Double$(33\mathrm{.}72)$;

Integer i$1=17$;

double num$1=($int$)($d$1+$ i$1)$;

$50\mathrm{.}0$

The code example contains an error and will not run.

$50$

$50\mathrm{.}72$

$16$ points

QUESTION $7$

Which of the following JOptionPane methods is used to display a pop$-$up dialog box with a displayed message?

showConfirmDialog

showMessageDialog

showInternalConfirmDialog

showInputDialog

$16$ points

QUESTION $8$

What $($if anything$)$ is wrong with the following Java code:

Integer i $=37$;

int x $=$ i$.$valueOf$("37")$;

The valueOf method is static and should be called on the Integer class itself.

There is nothing wrong with the above code.

An Integer object cannot be assigned a literal iteger value and the constructor must be used.

The valueOf method does not take any arguments, so it not possible to call the method this way.

$16$ points

QUESTION $9$

Which of the following statements would convert a String variable number$1$ into an int type:

Integer.valueOf$($number$1)$;

number$1.$valueOf$()$;

Integer.parseInt$($number$1)$;

number$1.$parseInt$()$;

int.valueOf$($number$1)$;

int.parseInt$($number$1)$;

$16$ points

QUESTION $10$

Assigning a primitive value to a Wrapper class results in automatic conversion called what:

Autoboxing

Steven

Shadowboxing

Unboxing