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

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

A). TypeError

B). ReferenceError

C). SyntaxError

D). RangeError

In which scenario would redeclaring a variable with 'var' lead to an unintended consequence?

A). When redeclaring in the same scope

B). When redeclaring in a different scope

C). When using 'strict mode'

D). When the variable has not been initialized

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

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 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 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

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

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

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