What will happen if you declare a 'let' variable inside a block and try to access it outside the block?

What will happen if you try to use a variable before declaring it with 'let'?

A). It will return undefined

B). It will return null

C). It will throw a ReferenceError

D). It will return NaN

Which of the following correctly describes variable hoisting with 'let' and 'const'?

A). Both 'let' and 'const' declarations are not hoisted

B). Only 'let' declarations are hoisted

C). Only 'const' declarations are hoisted

D). Both 'let' and 'const' declarations are hoisted but not initialized

Which of the following statements about 'let' and 'const' is false?

A). Both 'let' and 'const' are block-scoped

B). Both 'let' and 'const' cannot be redeclared in the same scope

C). 'let' can be reassigned, 'const' cannot

D). Both 'let' and 'const' can be redeclared in different scopes

How does 'let' differ from 'var' in terms of scope?

A). 'let' is function-scoped, 'var' is block-scoped

B). Both 'let' and 'var' are block-scoped

C). 'let' is block-scoped, 'var' is function-scoped

D). Both 'let' and 'var' are function-scoped

Given 'var a = 1; var a = 2;', what is the value of 'a' after these statements execute?

A). 1

B). 2

C). Undefined

D). Syntax Error

What will be the result of executing 'let x = 1; let x = 2;' in the same scope?

A). x will be 1

B). x will be 2

C). Syntax Error

D). Runtime Error

Why is it recommended to use 'let' and 'const' over 'var' in modern JavaScript?

A). 'let' and 'const' are function-scoped

B). 'let' and 'const' prevent variable hoisting

C). 'let' and 'const' are block-scoped, reducing potential errors

D). 'let' and 'const' are faster

How does the scope of 'var' differ from 'let' and 'const' inside a function?

A). 'var' is block-scoped, 'let' and 'const' are function-scoped

B). 'var', 'let', and 'const' are all block-scoped

C). 'var' is function-scoped, 'let' and 'const' are block-scoped

D). 'var' and 'let' are block-scoped, 'const' is function-scoped

What is the result of redeclaring a variable with 'var' in the same scope in JavaScript?

A). Syntax Error

B). The variable is overwritten

C). The variable remains unchanged

D). The program crashes

What error is thrown when attempting to redeclare a 'const' variable?

A). TypeError

B). ReferenceError

C). SyntaxError

D). RangeError