Which keyword allows block-level scope in ES6?
A). var
B). let
C). function
D). var and function
What is the primary difference between var and let?
A). Scope
B). Initialization
C). Data type
D). Assignment
What is the temporal dead zone in ES6?
A). Time between function calls
B). Period between variable declaration and initialization
C). Time between two loops
D). Interval between event listeners
Can a const variable be declared without an initial value?
A). Yes
B). No
C). Only in strict mode
D). Only if it is an object
What will the following code output: { let y = 5; { let y = 10; console.log(y); } }?
A). 5
B). 10
C). undefined
D). ReferenceError
Which keyword should be used for a variable that might be reassigned?
A). const
B). let
C). var
D). function
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 is the scope of a variable declared with let?
A). Global
B). Function
C). Block
D). Object
What error will the following code produce: const PI; PI = 3.14;?
A). SyntaxError
B). TypeError
C). ReferenceError
D). No error
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