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

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

Which of the following statements is true regarding redeclaring variables in JavaScript?

A). You can redeclare 'var' variables within the same scope without errors

B). You can redeclare 'let' variables within the same scope without errors

C). You can redeclare 'const' variables within the same scope without errors

D). None of the above

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

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

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 happens when you redeclare a variable with 'var' inside a function?

A). The variable is overwritten

B). The variable declaration is ignored

C). It throws an error

D). The function's scope is reset

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 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

Can you redeclare a 'var' variable in a different scope without error?

A). Yes

B). No

C). Only in strict mode

D). Only if the variable is not initialized