Q
What happens if you declare a const variable with the same name as an existing variable in JavaScript?

Answer & Solution

Answer: Option A
Solution:
Declaring a const variable with the same name as an existing variable in JavaScript throws a SyntaxError.
Related Questions on Average

How does hoisting differ between let and var declarations in JavaScript?

A). A. Both let and var variables are hoisted with their initial values

B). B. let variables are hoisted with their initial values, var variables are hoisted with undefined

C). C. let variables are not hoisted, var variables are hoisted with their initial values

D). D. Hoisting behavior is the same for let and var declarations

Which keyword allows hoisting of variables in JavaScript?

A). A. var

B). B. let

C). C. const

D). D. Both A and B

What is the purpose of the Temporal Dead Zone (TDZ) in JavaScript?

A). A. To prevent variable reassignment

B). B. To catch errors at compile time

C). C. To ensure variables are initialized before use

D). D. To reduce memory usage

What is the output of the following code snippet?

A). A. TypeError

B). B. 10

C). C. undefined

D). D. SyntaxError

What is the behavior of accessing a var variable within a block before its declaration in JavaScript?

A). A. ReferenceError is thrown

B). B. SyntaxError is thrown

C). C. undefined is printed

D). D. No error

Which of the following is true about const variables in JavaScript?

A). A. They can be reassigned after declaration

B). B. They can be accessed before declaration

C). C. They cannot be declared without an initial value

D). D. They cannot be hoisted

What is hoisting in JavaScript?

A). A. A process of lifting heavy objects

B). B. Moving variable and function declarations to the top of their scope

C). C. Reducing code size

D). D. None of the above

How does hoisting affect variable shadowing in JavaScript?

A). A. It allows variables with the same name in different scopes to coexist

B). B. It prevents variables with the same name in different scopes from coexisting

C). C. It has no effect on variable shadowing

D). D. It automatically renames variables with the same name

How does hoisting affect function declarations in JavaScript?

A). A. Function declarations are hoisted with their function bodies

B). B. Function declarations are hoisted but cannot be accessed before declaration

C). C. Function declarations are not hoisted

D). D. Hoisting has no effect on function declarations

What is the behavior of accessing a let variable before its declaration in JavaScript?

A). A. SyntaxError

B). B. ReferenceError

C). C. undefined

D). D. No error