Which keyword is used to declare block-scoped variables in JavaScript?
A). A. var
B). B. let
C). C. const
D). D. block
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
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 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 will be logged to the console after 1 second?
A). A. 0 1 2
B). B. 3 3 3
C). C. 0 0 0
D). D. Error
What happens if you try to reassign a value to a constant declared using const?
A). A. SyntaxError
B). B. TypeError
C). C. ReferenceError
D). D. No error, value is reassigned
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 will be logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
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 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