Fundamentals of Front End Development MCQs with Answers
Practice important Fundamentals of Front End Development MCQs with answers and explanations.
Chapter: 83
Q941:
Fill in the blank: To create a regular expression object, use _____ instead of new RegExp().
A. /()/
B. new RegExp()
C. []
D. {}
Correct Answer:
A
Chapter: 84
Q942:
What does subtracting a string from a string return in JavaScript?
A. Error
B. NaN
D. Undefined
Correct Answer:
B
Chapter: 84
Q943:
Fill in the blank: The === operator in JavaScript compares both _____ and type.
A. values
B. strings
C. numbers
D. objects
Correct Answer:
A
Chapter: 84
Q944:
Fill in the blank: To avoid errors due to missing function arguments, assign _____ values to parameters.
A. default
B. null
C. undefined
D. NaN
Correct Answer:
A
Chapter: 84
Q945:
Fill in the blank: Always end your switch statements with a _____ to handle unexpected cases.
A. default
B. case
C. break
D. continue
Correct Answer:
A
Chapter: 84
Q946:
What is the purpose of using parameter defaults in functions?
A. To handle missing arguments
B. To optimize code execution
C. To enforce strict type checks
D. To convert values automatically
Correct Answer:
A
Chapter: 84
Q947:
What will the switch statement default to if no cases match?
A. Unknown
B. Undefined
C. Error
Correct Answer:
A
Chapter: 84
Q948:
Fill in the blank: The === operator does not perform type _____ in JavaScript.
A. conversion
B. checking
C. coercion
D. casting
Correct Answer:
C
Chapter: 85
Q949:
What is a common mistake when using the assignment operator in an if statement?
A. Using == instead of =
B. Using === instead of =
C. Using = instead of ==
D. Using == instead of ===
Correct Answer:
C
Chapter: 85
Q950:
Fill in the blank: The == operator performs a comparison without considering _____ .
A. type
B. value
C. length
D. syntax
Correct Answer:
A
Chapter: 85
Q951:
What will the following switch statement do? switch(x) { case 10: alert("Hello"); }
A. Display "Hello"
B. Do nothing
C. Throw an error
D. Display "10"
Correct Answer:
A
Chapter: 85
Q952:
Fill in the blank: Adding numbers together in JavaScript is known as _____ , while combining strings is known as _____ .
A. addition, concatenation
B. concatenation, addition
C. multiplication, addition
D. addition, multiplication
Correct Answer:
B
Chapter: 85
Q953:
What is the result of var x = 10; var y = "5"; var z = x + y;?
A. 15
B. "15"
C. "105"
D. 105
Correct Answer:
C
Chapter: 85
Q954:
How can you correctly handle floating-point precision issues in JavaScript?
A. Multiply and divide
B. Use integers
C. Round values
D. Use parseFloat()
Correct Answer:
A
Chapter: 85
Q955:
What will happen if you mistakenly place a semicolon after an if statement?
A. The code block will execute unconditionally
B. The code block will not execute
C. An error will be thrown
D. Nothing will happen
Correct Answer:
A
Chapter: 85
Q956:
Fill in the blank: If you break a return statement into multiple lines, JavaScript will _____ .
A. return undefined
B. return null
C. throw an error
D. execute correctly
Correct Answer:
A
Chapter: 85
Q957:
What is the result of adding a named index to a JavaScript array?
A. The array becomes an object
B. The array length increases
C. The named index is added
D. The array remains unchanged
Correct Answer:
A
Chapter: 85
Q958:
What will var person = []; person["firstName"] = "John"; return for person[0]?
A. "John"
B. undefined
C. "firstName"
Correct Answer:
B
Chapter: 85
Q959:
Fill in the blank: In JavaScript, null is used for _____ and undefined is used for _____ .
A. objects, variables
B. variables, objects
C. functions, arrays
D. arrays, functions
Correct Answer:
A
Chapter: 86
Q960:
What is a performance improvement for loops in JavaScript?
A. Reduce the number of loop iterations
B. Move statements inside the loop
C. Reduce activity inside loops
D. Avoid using loops
Correct Answer:
C