Question 1

Suppose we want to condition an if statement on whether two String objects, referenced by stringOne and stringTwo, are the same. Which of the following is the correct way to achieve this?

Accepted Answer

A)  if(stringOne == stringTwo) 
B)  if(stringOne.compareTo(stringTwo)) 
C)  if(stringOne.equals(stringTwo)) 
D)  if(stringOne != stringTwo) 
E)  if(stringOne === stringTwo)

Question 2

The following snippet of code will not compile because the second part of the if statement needs to be on the second line.
if(a < b) System.out.println("a is less than b");

Accepted Answer

A) True 
 B)False

Question 3

Rewrite the following code fragment using a for loop instead of a while loop.
int i = 0;
while(i < 50) {
System.out.println(i);
i+=2;
}

Accepted Answer

The answer of Rewrite the following code fragment using a...

Question 4

Which of the following logical operators has the highest precedence?

Accepted Answer

A)  ! 
B)  && 
C)  || 
D)

Question 5

What is wrong with the following snippet of code? Rewrite it so it produces the correct output.
if(a < b)
		if(a == c)
			System.out.println(“a < b and a == c”);
	else
		System.out.println(“a is not less than b”);

Accepted Answer

The answer of What is wrong with the following snippet...

Question 6

A while statement always executes its loop body at least once.

Accepted Answer

A) True 
 B)False

Question 7

Write a code fragment that allows a user to continue inputting numbers until she enters a sentinel value of 0. Then print the sum of all the numbers she entered. You may assume that a Scanner object called input has already been created.

Accepted Answer

The answer of Write a code fragment that allows a...

Question 8

Which of the following best describes this code snippet?
 if (count != 400)
System.out.println("Hello World!");

Accepted Answer

A)  If the variable count is exactly equal to 400, "Hello World" will be printed. 
B)  If the variable count is not equal to 400, "Hello World" will be printed. 
C)  If the variable count is close to, but not greater than, 400, "Hello World" will be printed. 
D)  If the variable count is exactly equal to 399 or 401, "Hello World" will be printed. 
E)  This code will not compile.

Question 9

Let a and b be valid boolean expressions. Which of the following best describes the result of the expression a || b?

Accepted Answer

A)  It will evaluate to true if a evaluates to true and b evaluates to true. It will evaluate to false otherwise. 
B)  It will evaluate to false if a evaluates to false and b evaluates to false. It will evaluate to true otherwise. 
C)  It will evaluate to true if a evaluates to false and b evaluates to false. It will evaluate to true otherwise. 
D)  It will evaluate to true if a evaluates to false or b evaluates to false. It will evaluate to true otherwise. 
E)  None of the above statements correctly describes the evaluation of the expression.

Question 10

Rewrite the following for loop as a while loop.
for(int i = 0; i < MAX; i++)
//loop body

Accepted Answer

The answer of Rewrite the following for loop as a...

Question 11

The Scanner object can be used to read text files.

Accepted Answer

A) True 
 B)False

Question 12

A logical expression can be described by a ________________ that lists all possible combinations of values for the variables involved in an expression.

Accepted Answer

A)  palindrome 
B)  nested loop 
C)  equality operator 
D)  switch statement 
E)  truth table

Question 13

Write a short application that takes in a String from the user and prints it out backwards.

Accepted Answer

The answer of Write a short application that takes in...

Question 14

It is possible to implement a switch statement using if statements.

Accepted Answer

A) True 
 B)False

Question 15

A Scanner object can use delimiters other than a space.

Accepted Answer

A) True 
 B)False

Question 16

The relational operators should not be used to test the equality of objects.

Accepted Answer

A) True 
 B)False

Question 17

Write a for loop to print the even numbers from 1 to 100 (inclusive).

Accepted Answer

The answer of Write a for loop to print the...

Question 18

The ___________________ statement causes current iteration of a loop to stop and the condition to be evaluated again, either stopping the loop or causing the next iteration.

Accepted Answer

A)  stop 
B)  halt 
C)  continue 
D)  break 
E)  switch

Question 19

Which of the following for loop headers will cause the body of the loop to be executed 10 times?

Accepted Answer

A)  for(int i = 0; i <= 10; i++) 
B)  for(int i = 1; i < 10; i++) 
C)  for(int i = 1; i <= 11; i++) 
D)  for(int i = 0; i < 10; i++) 
E)  none of these for loops will execute the loop body 10 times

Question 20

A _______________ loop always executes its loop body at least once.

Accepted Answer

A)  while 
B)  for 
C)  do 
D)  repeat 
E)  There are no loop structures with this property in Java.

Exam 4: Conditionals and Loops

Suppose we want to condition an if statement on whether two String objects, referenced by stringOne and stringTwo, are the same. Which of the following is the correct way to achieve this?

The following snippet of code will not compile because the second part of the if statement needs to be on the second line. if(a < b) System.out.println("a is less than b");

Rewrite the following code fragment using a for loop instead of a while loop. int i = 0; while(i < 50) { System.out.println(i); i+=2; }

Which of the following logical operators has the highest precedence?

What is wrong with the following snippet of code? Rewrite it so it produces the correct output. if(a < b) if(a == c) System.out.println(“a < b and a == c”); else System.out.println(“a is not less than b”);

A while statement always executes its loop body at least once.

Write a code fragment that allows a user to continue inputting numbers until she enters a sentinel value of 0. Then print the sum of all the numbers she entered. You may assume that a Scanner object called input has already been created.

Which of the following best describes this code snippet? if (count != 400) System.out.println("Hello World!") ;

Let a and b be valid boolean expressions. Which of the following best describes the result of the expression a || b?

Rewrite the following for loop as a while loop. for(int i = 0; i < MAX; i++) //loop body

The Scanner object can be used to read text files.

A logical expression can be described by a ________________ that lists all possible combinations of values for the variables involved in an expression.

Write a short application that takes in a String from the user and prints it out backwards.

It is possible to implement a switch statement using if statements.

A Scanner object can use delimiters other than a space.

The relational operators should not be used to test the equality of objects.

Write a for loop to print the even numbers from 1 to 100 (inclusive).

The ___________________ statement causes current iteration of a loop to stop and the condition to be evaluated again, either stopping the loop or causing the next iteration.

Which of the following for loop headers will cause the body of the loop to be executed 10 times?

A _______________ loop always executes its loop body at least once.