Question 1

What is the output of the code snippet given below?
Int i = 0;
While (i != 11)
{
System.out.print(" " + i);
I = i + 2;
}
A) No output
B) 0 2 4 6 8
C) 10 12 14 16 18 …. (infinite loop)
D) 0 2 4 6 8 10 12 14 …. (infinite loop)

Accepted Answer

The loop increments 'i' by 2 each time, so it will never equal 11, causing an infinite loop starting from 0.

Question 2

What will be the result of running the following code fragment?
Int year = 0;
Double rate = 5;
Double principal = 10000;
Double interest = 0;
While (year < 10)
{
Interest = (principal * year * rate) / 100;
System.out.println("Interest " + interest);
}
A) The code fragment will display the interest calculated for nine years.
B) The code fragment will continue to display the calculated interest forever because the loop will never end.
C) The code fragment will not display the calculated interest and halt abruptly.
D) The code fragment will not display any output because it will not compile.

Accepted Answer

The loop will run indefinitely because the variable 'year' is never incremented, causing the condition 'year < 10' to always be true.

Question 3

What are the values of i and j after the following code snippet executes?
Int i = 60;
Int j = 50;
Int count = 0;
While (count < 5)
{
I = i + i;
I = i + 1;
J = j - 1;
J = j - j;
Count++;
}
System.out.println(i);
System.out.println(j);
A) i = 65, j = 1
B) i = 65, j = 45
C) i = 1951, j = 0
D) i = 1951, j = 45

Accepted Answer

The loop runs 5 times. Each iteration doubles i and adds 1, and sets j to 0. After 5 iterations, i becomes 1951 and j remains 0.

Question 4

Which of the following code snippets displays the output exactly 10 times?
A) int i = 0;
While (i < 10);
{
System.out.println("This is example 1.");
I++;
}
B) int i = 0;
While (i < 10)
{
System.out.println("This is example 2.");
I++;
}
C) int i = 0;
While (i < 10)
{
System.out.println("This is example 3.");
}
D) int i = 1;
While (i < 10)
{
System.out.println("This is example 4.");
I++;

Accepted Answer

The code snippet in option B correctly uses a while loop to print the statement 10 times, incrementing the counter `i` within the loop.

Question 5

How many times does the following code snippet display "Loop Execution"? for (int i = 0; i < 10; i++);
{
System.out.println("Loop Execution");
}
A) Ten times.
B) The code snippet does not run because of a compile error.
C) Infinite loop.
D) Only one time.

Accepted Answer

The semicolon after the for loop creates an empty loop body, so the block following it is not part of the loop and executes only once.

Question 6

How many times does the loop execute in the following code fragment?
Int i;
For (i = 0; i < 50; i = i + 4)
{
System.out.println(i);
}
A) 11
B) 12
C) 13
D) 14

Accepted Answer

The answer of How many times does the loop execute...

Question 7

What is the output of the code snippet given below?
Int i = 0;
While (i != 11)
{
System.out.print(i + " ");
I = i + 3;
}
A) No output
B) 0 3 6 9 12 15 18
C) 0 1 3 5 7 9
D) 0 3 6 9 …. (infinite loop)

Accepted Answer

The loop will continue to execute as long as i is not equal to 11. In each iteration, i is incremented by 3. So, the loop will execute 4 times, printing 0, 3, 6, and 9. After the fourth iteration, i will be equal to 12, which is not equal to 11. So, the loop will terminate.

Question 8

Select the statement that correctly completes the loop in this code snippet.
Int years = 20;
Double balance = 10000;
While (years > 0)
{
__________
Double interest = balance * rate / 100;
Balance = balance + interest;
}
A) years++;
B) years--;
C) balance++;
D) balance--;

Accepted Answer

The loop is intended to run for a specific number of years, decrementing the 'years' variable each time the loop executes. Therefore, 'years--' is the correct statement to decrease the count of years until it reaches zero.

Question 9

What is the output of the following code snippet?
Int i = 1;
While (i != 9)
{
System.out.print(i + " ");
I++;
If (i == 9)
{
System.out.println("End");
}
}
A) 1 End
B) 1 End (infinite loop)
C) 1 2 3 4 5 6 7 8 End
D) 1 2 3 4 5 6 7 8 End (infinite loop)

Accepted Answer

The loop prints numbers from 1 to 8, and when i becomes 9, it prints "End" and exits the loop.

Question 10

Which of the following is considered a loop with a bound that could be problematic?
A) for (i = 1; i != n; i++)
B) for (years = n; years < 0; years--)
C) for (i = 1; i <= n; i++)
D) for (int i = 1; i <= 10; i++)

Accepted Answer

The loop condition `i != n` can be problematic because if `n` is not reached exactly, the loop could become infinite.

Question 11

What values does counter variable i assume when this loop executes? for (int i = 20; i >= 2; i = i - 6)
{
System.out.print(i + ",");
}
A) 20, 14, 8, 2
B) 20, 14, 8, 2, -4
C) 20, 14, 8
D) 14, 8, 2

Accepted Answer

The answer of What values does counter variable i assume...

Question 12

When hand-tracing a portion of code, which statement about Boolean conditions is true?
A) They typically are too complex to be evaluated.
B) They do not need to be monitored because their result usually is not stored in a variable.
C) It is rare to encounter a Boolean condition.
D) They are crucial to evaluate since they determine if-statement conditions and looping.

Accepted Answer

Boolean conditions are essential to evaluate because they determine the flow of control in if-statements and loops, which are fundamental to understanding how the code executes.

Question 13

What is the output of the code snippet given below?
Int i;
Int j = 0;
For (i = 0; i < 5; i++)
{
If (i % 2 == 0)
{
I = i + 2;
J++;
}
Else
{
I++;
J = j + 2;
}
J++;
}
System.out.println("i=" + i + ", j=" + j);
A) i=7, j =7
B) i =7, j =6
C) i =6, j =7
D) i =5, j =5

Accepted Answer

The answer of What is the output of the code...

Question 14

What changes do you need to make in the following code snippet to display "Let us learn Java" exactly 10 times?
Int i = 0;
While (i <= 10)
{
System.out.println("Let us learn Java");
I++;
}
A) while (i < 9)
B) while (i < 11)
C) while (i < 12)
D) int i = 1;

Accepted Answer

The answer of What changes do you need to make...

Question 15

When hand tracing, drawing a line through the value stored in a variable means that
A) The value stored there has changed to something new
B) The variable is the wrong data type for the code being executed
C) The expression being evaluated uses that variable
D) The variable must be inside a loop

Accepted Answer

Drawing a line through a variable's value in hand tracing indicates that the value has been updated or changed to a new value.

Question 16

What is the output of the following code snippet?
Int f1 = 0;
Int f2 = 1;
Int fRes;
System.out.print(f1 + " ");
System.out.print(f2 + " ");
For (int i = 1; i < 10; i++)
{
FRes = f1 + f2;
System.out.print(fRes + " ");
F1 = f2;
F2 = fRes;
}
System.out.println();
A) 0 1 5 7 9 11 13 15 17 19
B) 0 1 1 2 3 5 8 13 21 34 55
C) 0 1 4 6 8 10 12 14 16 18
D) 0 1 6 7 9 12 14 17 19 21

Accepted Answer

The code snippet prints the first 10 numbers of the Fibonacci sequence starting from 0 and 1.

Question 17

The process of hand-tracing code is valuable because
A) It is usually faster than just running the code.
B) It is the best way to design an algorithm.
C) You must already have a working program in order to do it.
D) It gives valuable insight that you do not get by running the code.

Accepted Answer

Hand-tracing code allows you to manually follow the logic and flow of a program, which can reveal insights into how the code operates, potential errors, and areas for optimization that might not be immediately apparent when simply running the code.

Question 18

What is the output of this code snippet? String str = "ABCabc";
Char ch;
Int i = 0;
While (i < str.length())
{
Ch = str.charAt(i);
If (Character.isLowerCase(ch))
{
System.out.print(i + " ");
}
Else
{
I++;
}
}
A) 3 4 5
B) 3
C) 3 3 3 3 3 ... (infinite loop)
D) 0 1 2

Accepted Answer

The code enters an infinite loop because the increment of 'i' only occurs in the 'else' block, which is never reached for lowercase characters.

Question 19

When hand-tracing the loop in the code snippet below, which variables are important to evaluate?
Int i = 10;
Int j = 5;
Int k = -10;
Int sum = 0;
While (i > 0)
{
Sum = sum + i + j;
I--;
System.out.println("Iteration: " + i);
}
A) The variables i and j
B) The variables i and sum
C) The variables i, j, and k
D) The variables j and k

Accepted Answer

The variable 'i' controls the loop iteration, and 'sum' accumulates the result, making them crucial for evaluating the loop's behavior.

Question 20

In the __________ loop header, you can include multiple update expressions, separated by commas, but it is not recommended.
A) do
B) while
C) for
D) do.

Accepted Answer

In a 'for' loop, you can include multiple update expressions in the loop header, separated by commas. However, it is generally not recommended for readability and maintainability reasons.

Quiz 6: Loops

What is the output of the code snippet given below? Int i = 0; While (i != 11) { System.out.print(" " + i) ; I = i + 2; }

What will be the result of running the following code fragment? Int year = 0; Double rate = 5; Double principal = 10000; Double interest = 0; While (year < 10) { Interest = (principal * year * rate) / 100; System.out.println("Interest " + interest) ; }

What are the values of i and j after the following code snippet executes? Int i = 60; Int j = 50; Int count = 0; While (count < 5) { I = i + i; I = i + 1; J = j - 1; J = j - j; Count++; } System.out.println(i) ; System.out.println(j) ;

Which of the following code snippets displays the output exactly 10 times?

How many times does the following code snippet display "Loop Execution"? for (int i = 0; i < 10; i++) ; { System.out.println("Loop Execution") ; }

How many times does the loop execute in the following code fragment? Int i; For (i = 0; i < 50; i = i + 4) { System.out.println(i) ; }

What is the output of the code snippet given below? Int i = 0; While (i != 11) { System.out.print(i + " ") ; I = i + 3; }

Select the statement that correctly completes the loop in this code snippet. Int years = 20; Double balance = 10000; While (years > 0) { __________ Double interest = balance * rate / 100; Balance = balance + interest; }

What is the output of the following code snippet? Int i = 1; While (i != 9) { System.out.print(i + " ") ; I++; If (i == 9) { System.out.println("End") ; } }

Which of the following is considered a loop with a bound that could be problematic?

What values does counter variable i assume when this loop executes? for (int i = 20; i >= 2; i = i - 6) { System.out.print(i + ",") ; }

When hand-tracing a portion of code, which statement about Boolean conditions is true?

What is the output of the code snippet given below? Int i; Int j = 0; For (i = 0; i < 5; i++) { If (i % 2 == 0) { I = i + 2; J++; } Else { I++; J = j + 2; } J++; } System.out.println("i=" + i + ", j=" + j) ;

What changes do you need to make in the following code snippet to display "Let us learn Java" exactly 10 times? Int i = 0; While (i <= 10) { System.out.println("Let us learn Java") ; I++; }

When hand tracing, drawing a line through the value stored in a variable means that

What is the output of the following code snippet? Int f1 = 0; Int f2 = 1; Int fRes; System.out.print(f1 + " ") ; System.out.print(f2 + " ") ; For (int i = 1; i < 10; i++) { FRes = f1 + f2; System.out.print(fRes + " ") ; F1 = f2; F2 = fRes; } System.out.println() ;

The process of hand-tracing code is valuable because

What is the output of this code snippet? String str = "ABCabc"; Char ch; Int i = 0; While (i < str.length() ) { Ch = str.charAt(i) ; If (Character.isLowerCase(ch) ) { System.out.print(i + " ") ; } Else { I++; } }

When hand-tracing the loop in the code snippet below, which variables are important to evaluate? Int i = 10; Int j = 5; Int k = -10; Int sum = 0; While (i > 0) { Sum = sum + i + j; I--; System.out.println("Iteration: " + i) ; }

In the __________ loop header, you can include multiple update expressions, separated by commas, but it is not recommended.