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 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 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
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 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 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 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
What will be logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
Which of the following statements about const is true?
A). A. Variables declared with const can be reassigned
B). B. const variables have function scope
C). C. const variables cannot be used in loops
D). D. const variables are block-scoped