What is the primary difference between var and let?

What is the output of the following code: let z = 3; z = 5; console.log(z);?

A). 3

B). 5

C). undefined

D). ReferenceError

Can const be used for objects and arrays?

A). No

B). Yes

C). Only for arrays

D). Only for objects

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

Can a variable declared with let be hoisted?

A). Yes, partially

B). No

C). Yes, fully

D). Only in strict mode

What is the scope of a variable declared with let?

A). Global

B). Function

C). Block

D). Object

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 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 const variables be reassigned in nested scopes?

A). Yes

B). No

C). Only if they are strings

D). Only in strict mode

Which keyword allows block-level scope in ES6?

A). var

B). let

C). function

D). var and function