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 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 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

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

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

Which of the following is a characteristic of 'const' variables?

A). They can be redeclared

B). They can be reassigned

C). They cannot be redeclared but can be reassigned

D). They cannot be redeclared or reassigned

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

A). TypeError

B). ReferenceError

C). SyntaxError

D). RangeError

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 correctly describes variable hoisting with 'var'?

A). 'var' declarations are not hoisted

B). Only the variable declaration is hoisted, not the initialization

C). Both declaration and initialization are hoisted

D). Only in strict mode 'var' declarations are hoisted

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 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