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 logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
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 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
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
What will be the output of the code above?
A). A. 10
B). B. 20
C). C. Error
D). D. Undefined
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
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;
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