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 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 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
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
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 logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
Which statement is true regarding the const keyword in JavaScript?
A). A. Constants declared with const are hoisted
B). B. Constants declared with const can be reassigned
C). C. Constants declared with const have global scope
D). D. Constants declared with const are immutable
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 logged to the console?
A). A. 'Alice'
B). B. 'Bob'
C). C. TypeError
D). D. Undefined
What will be the output of the code above?
A). A. 10
B). B. 20
C). C. Error
D). D. Undefined