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 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 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

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

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

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 '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 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