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
Which keyword is used to declare block-scoped variables in JavaScript?
A). A. var
B). B. let
C). C. const
D). D. block
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
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 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. [1, 2, 3, 4]
B). B. [1, 2, 3]
C). C. [1, 2, 3, 4, 5]
D). D. Error
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
What will be the output of the code above?
A). A. 10
B). B. 20
C). C. Error
D). D. Undefined
What will be logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
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