Java2

1.

1 point

When importing another package into a class you must import the entire package as well as the package classes that will be called.

True

False

2.

1 point

The following defines a class keyword:

Provides the compiler information that identifies outside classes used within the current class.

Precedes the name of the class.

Defines where this class lives relative to other classes, and provides a level of access control.

3.

1 point

The six relational operators in Java are:

>,<,=,!=,<=,>=

>,<,==,!=,<=,>=

>,<,=,!,<=,>=

>,<,=,!=,=<,=>

4.

1 point

A counter used in a for loop cannot be initialized within the For loop statement.

True

False

5.

1 point

Which of the following statements correctly assigns "3 times 10 to the 4th power" to the variable number?

double number=3*10e4;

double number=3(e4)

double number=3e4;

double number=3*10^4

6.

1 point

Given the code below, which of the following would equate to true?
String s1 = "yes";
String s2 = "yes";
String s3 = new String(s1); Choose all correct.

s1 == s2

s1 = s2

s1.equals(s2)

s3.equals(s1)

7.

1 point

What is one significant difference between a while loop and a do-while loop?

There is no difference between a DO-WHILE loop and a WHILE loop.

A DO-WHILE loop includes an int that serves as a counter and a WHILE loop does not.

A DO-WHILE loop will always execute the code at least once, even if the conditional statement for the WHILE is never true. A WHILE loop is only executed if the conditional statement is true.

A DO-WHILE loop does not exist in Java and a WHILE loop does.

8.

1 point

Which of the following are types of loops in Java?

while

do-while

if-else

for

9.

1 point

Which of the following defines a driver class?

Contains a main method and other static methods.

Contains classes that define objects.

None of the above.

10.

1 point

How would you use the ternary operator to rewrite this if statement?
if (gender == "male")
System.out.print("Mr.");
else
System.out.print("Ms.");

(gender == "male") ? "Mr." : "Ms." ;

System.out.print( (gender == "male") ? "Mr." : "Ms." );

System.out.print( (gender == "male") ? "Ms." : "Mr." );

(gender == "male") ? "Ms." : "Mr." ;

11.

1 point

Which line of Java code properly calculates the volume of a cone using
v=1/3 pi r2 h
where r and h are Java primitive integers?

double V=1/3*3.14*r*r*h;

double V=1/3*3.14*r(2)*h

double V=(double)1/3*Math.PI*Math.pow(2,r)*h;

double V=(double)1/3*Math.PI*Math.pow(r,2)*h;

12.

1 point

It is necessary to end all loops at some point in your Java program.

True

False

13.

1 point

For both the if-else construct and the for loop, it is true to say that when the condition statement is met, the construct is exited. True or False?

True

False

14.

1 point

In Java, each case segment of a switch statement requires the keyword break to avoid "falling through".

True

False

15.

1 point

What will the method methodA print to the screen?
public Class A
{
int g=5;//global variable
public void methodA()
{
int g=6;
System.out.println(g*3);
}
}

15

18

3

6

16.

1 point

The three logic operators in Java are:

!=,=,==

&,|,=

&&, ||, !

&&,!=,=

17.

1 point

The == operator can be used to compare two String objects. The result is always true if the two strings are identical.

True

False

18.

1 point

In a for loop, the counter is automatically incremented after each loop iteration. True or False?

True

False

19.

1 point

Determine whether this boolean expression evaluates to true or false:
!(3<4&&5>6||6<=6&&7-1==6)

True

False

20.

1 point

How would you use the ternary operator to rewrite this if statement?
if (skillLevel > 5)
numberOfEnemies = 10;
else
numberOfEnemies = 5;

numberOfEnemies = ( skillLevel > 5) ? 10 : 5; (*)

numberOfEnemies = ( skillLevel > 5) ? 5 : 10;

numberOfEnemies = ( skillLevel < 5) ? 10 : 5;

numberOfEnemies = ( skillLevel >= 5) ? 5 : 10;

21.

1 point

Identify which situation could be an example of a while loop.

Petting each animal at the pet store one at a time until all the animals have been petted.

All of the above.

Taking coins out of a pile one at a time and adding their value to the total until there are no more coins in the pile to add.

Attending class while school is not over for the day.

22.

1 point

Consider the following code snippet. What is printed?
String ocean = new String("Atlantic Ocean");
System.out.println(ocean.indexOf('a'));

3

11

0

2

23.

1 point

Eclipse provides views to help you navigate a hierarchy of information.

True

False

24.

1 point

Eclipse provides an edit area to help you navigate a hierarchy of information.

True

False

25.

1 point

The String methods equals and compareTo perform the exact same function.

True

False

26.

1 point

The syntax below represents a valid initialization of a for loop counter. True or False?
public class ForLoop {
public static void main (String args[])
{
for (int i=10; i <20; i++)
{System.out.println("i: "+i); }
}
}

True

False

27.

1 point

In an if-else construct, the condition to be evaluated must be contained within parentheses.

True

False

28.

1 point

What is the function of the word "break" in Java?

It stops the program from running.

It continues onto the next line of code.

It exits the current loop or case statement.

It does not exist in Java.

29.

1 point

When Eclipse launches, the Welcome page displays. Once this page is closed you cannot return to the resources available on this page.

True

False

30.

1 point

What is the difference between the symbols = and == ?

There is no difference.

The symbol == is used to assign values to variables and the = is used in declarations.

The symbol = is used in if statements and == is used in loops.

The = is use to assign values to variables and the == compares values.

31.

1 point

What is a loop?

A segment of code that may only ever be executed once per call of the program.

A keyword used to skip over the remaining code.

None of the above.

A set of logic that is repeatedly executed until a certain condition is met.

32.

1 point

Which of the following correctly initializes a for loop that executes 5 times?

for(int i = 1; i < 6; i++)

for(int i = 0; i == 6; i++)

for(int i = 1; i < 5; I++)

for(int i = 0; i < 5; I++)

33.

1 point

Given the following declaration: int z=5,m=6;
Which line of Java code properly casts one type into another without data loss?

double x= double z/m;

double x=(double)z/m;

double x=(double)(z/m);

double x=z/m;

34.

1 point

Which of the following correctly initializes an instance of Scanner, called "in", that reads input from the console screen?

Scanner in = new Scanner("System.in");

Scanner in = new Scanner(System.in);

Scanner in = Scanner(System.in);

System.in in = new Scanner();

35.

1 point

The following code fragment properly implements the switch statement. True or false?
default(input)
switch '+':
answer+=num;
break;
case '-':
answer-=num;
break;
!default
System.out.println("Invalid input");

True

False