What is the primary advantage of using block scope in JavaScript?
A). Reducing code size
B). Preventing variable hoisting
C). Avoiding global variables
D). Improving performance
Which statement about JavaScript's const is true?
A). const variables can be redeclared
B). const variables are globally scoped
C). const variables are mutable
D). const variables cannot be reassigned
Which keyword is used to declare block-scoped variables in JavaScript?
A). var
B). let
C). const
D). block
In JavaScript, const variables are not hoiste What does this mean?
A). They are hoisted to the top of the block
B). They cannot be used before declaration
C). They are accessible in nested scopes
D). They are block-scoped variables
What happens if you try to reassign a value to a constant declared using const?
A). SyntaxError
B). TypeError
C). ReferenceError
D). No error, value is reassigned
What will be the output of the code above?
A). 30
B). 31
C). TypeError
D). Undefined
Which of the following is NOT an example of a block in JavaScript?
A). Function body
B). if statement body
C). while loop body
D). Object literal
What will be the output of the code above?
A). 10
B). 20
C). Error
D). Undefined
What does the const keyword signify in JavaScript?
A). Constant variable
B). Mutable variable
C). Global variable
D). Block-scoped variable
Which of the following best describes the behavior of JavaScript's const keyword?
A). It prevents variables from being redeclared
B). It ensures variables cannot be reassigned
C). It provides global scope for variables
D). It allows variables to change their data type