Fundamentals of Front End Development MCQs with Answers
Practice important Fundamentals of Front End Development MCQs with answers and explanations.
Chapter: 75
Q841:
What is the main difference between a while loop and a do/while loop?
A. The do/while loop executes the code block once before checking the condition
B. The while loop always executes at least once
C. The do/while loop does not check the condition
D. The while loop executes a fixed number of times
Correct Answer:
A
Chapter: 75
Q842:
In a while loop, what happens if the condition is false initially?
A. The code block inside the loop will not execute
B. The loop will execute once and then terminate
C. The loop will execute indefinitely
D. The loop will generate an error
Correct Answer:
A
Chapter: 75
Q843:
What is the output of the following while loop? while (i < 3) { text += i + " "; i++; } (assuming i starts at 0)
A. "0 1 2 3"
B. "1 2 3"
C. "0 1 2"
D. "0 1 2 3 4"
Correct Answer:
C
Chapter: 75
Q844:
Fill in the blank: In a while loop, if the condition is always true, the loop will result in a _____.
A. Syntax error
B. Infinite loop
C. Conditional exit
D. Variable initialization
Correct Answer:
B
Chapter: 75
Q845:
What is the output of the following do/while loop? do { text += i + " "; i++; } while (i < 4); (assuming i starts at 0)
A. "0 1 2 3"
B. "0 1 2 3 4"
C. "1 2 3"
D. "0 1 2"
Correct Answer:
A
Chapter: 75
Q846:
In the following code snippet, what will happen if i starts at 5 in a while loop with condition while (i < 10) { text += i + " "; i++; }?
A. The loop will not execute
B. The loop will execute 5 times
C. The loop will execute 10 times
D. The loop will execute 1 time
Correct Answer:
A
Chapter: 75
Q847:
Fill in the blank: A do/while loop checks its condition _____.
A. After the code block is executed
B. Before the code block is executed
C. Only once
D. After every iteration
Correct Answer:
A
Chapter: 75
Q848:
What happens if the condition in a do/while loop is always false?
A. The loop will execute at least once
B. The loop will execute indefinitely
C. The loop will not execute
D. The code will throw an error
Correct Answer:
A
Chapter: 76
Q849:
What does the break statement do in a loop?
A. Exits the loop entirely
B. Skips the current iteration
C. Repeats the loop
D. Jumps to the next loop
Correct Answer:
A
Chapter: 76
Q850:
What happens when the continue statement is executed in a loop?
A. It exits the loop and moves to the next block of code
B. It skips the current iteration and continues with the next iteration
C. It exits the entire program
D. It repeats the current iteration
Correct Answer:
B
Chapter: 76
Q851:
In the following loop, what is the output if i equals 3? for (i = 0; i < 10; i++) { if (i === 3) { break; } text += "The number is " + i + "<br>"; }
A. The number is 0, The number is 1, The number is 2
B. The number is 0, The number is 1, The number is 2, The number is 3
C. The number is 0, The number is 1, The number is 2, The number is 3, The number is 4
D. The number is 0, The number is 1, The number is 2, The number is 3, The number is 4, The number is 5
Correct Answer:
A
Chapter: 76
Q852:
What will be the output of the following code? for (i = 0; i < 10; i++) { if (i === 3) { continue; } text += "The number is " + i + "<br>"; }
A. The number is 0, The number is 1, The number is 2, The number is 4, The number is 5, The number is 6, The number is 7, The number is 8, The number is 9
B. The number is 0, The number is 1, The number is 2, The number is 3, The number is 4, The number is 5, The number is 6, The number is 7, The number is 8, The number is 9
C. The number is 0, The number is 1, The number is 2, The number is 3
D. The number is 0, The number is 1, The number is 2, The number is 4
Correct Answer:
A
Chapter: 76
Q853:
Fill in the blank: The break statement in a loop will stop the loop's execution and _____.
A. Jump to the next iteration
B. Continue with the next iteration
C. Exit the loop and proceed with the following code
D. Repeat the current iteration
Correct Answer:
C
Chapter: 76
Q854:
What is the result of using continue in the following loop if i equals 3? for (i = 0; i < 10; i++) { if (i === 3) { continue; } text += "The number is " + i + "<br>"; }
A. The number 3 will be included in the output
B. The loop will exit when i equals 3
C. The number 3 will be skipped in the output
D. The loop will execute indefinitely
Correct Answer:
C
Chapter: 76
Q855:
What will the output be if i is initially 0 and the loop uses the continue statement when i equals 3?
A. The number is 0, The number is 1, The number is 2, The number is 4, The number is 5, The number is 6, The number is 7, The number is 8, The number is 9
B. The number is 0, The number is 1, The number is 2, The number is 3, The number is 4, The number is 5, The number is 6, The number is 7, The number is 8, The number is 9
C. The number is 0, The number is 1, The number is 2, The number is 3
D. The number is 0, The number is 1, The number is 2, The number is 3, The number is 4
Correct Answer:
A
Chapter: 76
Q856:
Fill in the blank: The break statement is used to _____.
A. Skip one iteration of a loop
B. Exit the current loop
C. Continue with the next iteration of a loop
D. Initialize the loop variable
Correct Answer:
B
Chapter: 77
Q857:
What data type does the typeof operator return for a string?
A. string
B. number
C. boolean
D. object
Correct Answer:
A
Chapter: 77
Q858:
What is the data type of typeof [1,2,3,4]?
A. string
B. number
C. boolean
D. object
Correct Answer:
D
Chapter: 77
Q859:
What is the data type of null according to the typeof operator?
A. null
B. object
C. undefined
D. function
Correct Answer:
B
Chapter: 77
Q860:
Fill in the blank: The typeof operator always returns a _____ containing the type of the operand.
A. number
B. string
C. boolean
D. object
Correct Answer:
B