What will be the output of the following code: let x = 10; { let x = 20; } console.log(x);?

What will the following code output: { let y = 5; { let y = 10; console.log(y); } }?

A). 5

B). 10

C). undefined

D). ReferenceError

Are variables declared with let and const accessible before they are declared?

A). Yes

B). No

C). Only in strict mode

D). Only if they are numbers

Can a variable declared with let be hoisted?

A). Yes, partially

B). No

C). Yes, fully

D). Only in strict mode

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

Which keyword allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function

Can const variables be reassigned in nested scopes?

A). Yes

B). No

C). Only if they are strings

D). Only in strict mode

Which keyword is used to declare a read-only named constant?

A). let

B). var

C). const

D). static

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

What error will the following code produce: const PI; PI = 3.14;?

A). SyntaxError

B). TypeError

C). ReferenceError

D). No error

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