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 does the const keyword signify in JavaScript?
A). A. Constant variable
B). B. Mutable variable
C). C. Global variable
D). D. Block-scoped variable
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
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 keyword is used to declare a constant array in JavaScript?
A). A. let
B). B. const
C). C. var
D). D. array
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 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
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 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. 30
B). B. 31
C). C. Error
D). D. Undefined