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

Answer & Solution

Answer: Option C
Solution:
It is recommended to use 'let' and 'const' over 'var' because they are block-scoped, reducing the risk of errors related to variable hoisting and scope leakage.
Related Questions on Average

What happens if you try to redeclare a 'const' variable in JavaScript?

A). It will throw an error

B). The variable is overwritten

C). The variable is converted to 'let'

D). The program continues with a warning

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

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

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

Can you redeclare a 'let' variable in the same scope in JavaScript?

A). Yes

B). No

C). Only in strict mode

D). Only in non-strict mode

What does 'TDZ' stand for in the context of JavaScript?

A). Temporary Declaration Zone

B). Temporal Dead Zone

C). Temporary Dead Zone

D). Temporal Declaration Zone

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

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

A). It will return undefined

B). It will throw a ReferenceError

C). It will return null

D). It will be accessible outside the block

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

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

A). TypeError

B). ReferenceError

C). SyntaxError

D). RangeError