Q
What is the primary advantage of using block scope in JavaScript?

Answer & Solution

Answer: Option C
Solution:
Block scope in JavaScript primarily helps in avoiding global variables, reducing the risk of variable naming conflicts and unintentional changes to global state.
Related Questions on Average

How can you declare a constant named PI with a value of 3.14 in JavaScript using const?

A). A. const PI = 3.14;

B). B. PI = 3.14;

C). C. let PI = 3.14;

D). D. var PI = 3.14;

What will be logged to the console?

A). A. 'John'

B). B. 'Jane'

C). C. Error

D). D. Undefined

Which of the following is NOT an example of a block in JavaScript?

A). A. Function body

B). B. if statement body

C). C. while loop body

D). D. Object literal

Which of the following statements is true about constants declared using const?

A). A. They can be reassigned multiple times

B). B. They are hoisted to the top

C). C. They are mutable

D). D. They are immutable

What will be the output of the code above?

A). A. 30

B). B. 31

C). C. Error

D). D. Undefined

What is the purpose of using block scope in JavaScript?

A). A. To declare constants

B). B. To prevent variable hoisting

C). C. To improve code performance

D). D. To create global variables

What will be the output of the code above?

A). A. 10

B). B. 20

C). C. Error

D). D. Undefined

Which keyword is used to declare a constant array in JavaScript?

A). A. let

B). B. const

C). C. var

D). D. array

What will be logged to the console?

A). A. 'Alice'

B). B. 'Bob'

C). C. TypeError

D). D. Undefined

What does the const keyword signify in JavaScript?

A). A. Constant variable

B). B. Mutable variable

C). C. Global variable

D). D. Block-scoped variable