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

Answer & Solution

Answer: Option A
Solution:
Redeclaring a 'const' variable in the same scope will throw a SyntaxError, as 'const' variables cannot be reassigned or redeclared.
Related Questions on Average

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 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

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

A). 'let' and 'const' are function-scoped

B). 'let' and 'const' prevent variable hoisting

C). 'let' and 'const' are block-scoped, reducing potential errors

D). 'let' and 'const' are faster

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

A). TypeError

B). ReferenceError

C). SyntaxError

D). RangeError

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 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 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 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