Which of the following statements about const and objects is true?
A). Objects declared with const are immutable
B). Properties of objects declared with const can be changed
C). The reference of objects declared with const can be changed
D). const cannot be used with objects
What will be the output of the following code: let x = 10; { let x = 20; } console.log(x);?
A). 10
B). 20
C). undefined
D). ReferenceError
What will the following code output: { let y = 5; { let y = 10; console.log(y); } }?
A). 5
B). 10
C). undefined
D). ReferenceError
What is the primary difference between var and let?
A). Scope
B). Initialization
C). Data type
D). Assignment
Can const be used for objects and arrays?
A). No
B). Yes
C). Only for arrays
D). Only for objects
What happens if you try to access a let variable before its declaration?
A). Returns undefined
B). Throws a ReferenceError
C). Returns null
D). Returns an empty string
Which keyword should be used for a variable that might be reassigned?
A). const
B). let
C). var
D). function
Can const variables be reassigned in nested scopes?
A). Yes
B). No
C). Only if they are strings
D). Only in strict mode
What is the value of a const variable once it is assigned?
A). Can be changed later
B). Cannot be changed later
C). Depends on the data type
D). Undefined initially
What error will the following code produce: const PI; PI = 3.14;?
A). SyntaxError
B). TypeError
C). ReferenceError
D). No error