Answer & Solution
Answer: Option B
Solution:
Block scope in JavaScript is used to prevent variable hoisting and ensure variables are only accessible within the block they are defined in.
Q
What is the purpose of using block scope in JavaScript?
Related Questions on Average
What is the primary advantage of using block scope in JavaScript?
A). A. Reducing code size
B). B. Preventing variable hoisting
C). C. Avoiding global variables
D). D. Improving performance
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;
Which of the following statements is true about block scope in JavaScript?
A). A. Variables declared with let have global scope
B). B. Variables declared with let have function scope
C). C. Variables declared with let are block-scoped
D). D. Variables declared with let are hoisted
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 the output of the code above?
A). A. [1, 2, 3, 4]
B). B. [1, 2, 3]
C). C. [1, 2, 3, 4, 5]
D). D. Error
What will be the output of the code above?
A). A. 10
B). B. 20
C). C. Error
D). D. Undefined
What is the primary difference between const and let in JavaScript?
A). A. const variables can be reassigned
B). B. let variables are block-scoped
C). C. const variables are hoisted
D). D. let variables are immutable
What is the purpose of using the const keyword in JavaScript?
A). A. To declare variables with global scope
B). B. To declare block-scoped variables
C). C. To declare variables that can be reassigned
D). D. To declare variables that cannot be reassigned
What will be logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
What will be logged to the console?
A). A. 'Alice'
B). B. 'Bob'
C). C. TypeError
D). D. Undefined