How does 'let' handle variable re-declaration in the same scope?

What is the default scope of variables declared with the 'var' keyword in JavaScript?

A). Block scope

B). Function scope

C). Module scope

D). Block and function scope

Which keyword is used for declaring variables that should not change?

A). var

B). let

C). const

D). all of the above

Which keyword should be used by default to declare variables in modern JavaScript?

A). var

B). let

C). const

D). Either B or C

What will happen if you declare a variable without 'var', 'let', or 'const'?

A). Creates a global variable

B). Creates a block-scoped variable

C). Creates a function-scoped variable

D). Throws an error

What will be the output of the following code: const d = 90; d = 100; console.log(d);

A). 90

B). 100

C). Error

D). undefined

What is the scope of a variable declared with 'let' inside a loop?

A). Global

B). Function

C). Loop block

D). Entire script

Which of the following statements is true about 'const'?

A). It allows re-declaration

B). It allows reassignment

C). It is block-scoped

D). It is function-scoped

What will be the output of the following code: console.log(a); var a = 50;

A). 50

B). undefined

C). Error

D). null

Which keyword allows block-scoped variable declaration?

A). var

B). let

C). const

D). Both B and C

What will be the output of the following code: const z = 30; z = 40; console.log(z);

A). 30

B). 40

C). Error

D). undefined