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 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
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 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 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
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 the output of the code above?
A). A. 30
B). B. 31
C). C. Error
D). D. Undefined
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
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