Which keyword allows redeclaring variables in JavaScript?

Which keyword should you use to avoid redeclaring variables in JavaScript?

A). A. var

B). B. let

C). C. const

D). D. Both B and C

What is the behavior when redeclaring a variable with let or const in JavaScript?

A). A. SyntaxError is thrown

B). B. No effect on the variable

C). C. Variable value is changed

D). D. Variable reference is updated

How can you avoid redeclaring variables in JavaScript?

A). A. Always use var for variable declarations

B). B. Declare variables once and avoid redeclaration

C). C. Declare variables multiple times for clarity

D). D. Use the same variable name for different values

What is variable redeclaring in JavaScript?

A). A. Changing the value of a variable

B). B. Declaring the same variable again within the same scope

C). C. Deleting a variable

D). D. Assigning multiple values to a variable

How can you handle cases where you accidentally redeclare a variable in JavaScript?

A). A. Use var for all variable declarations

B). B. Use meaningful variable names to avoid conflicts

C). C. Use let or const for variable declarations within the same scope

D). D. Both B and C

What happens if you declare a variable with var and redeclare it with let or const within the same scope in JavaScript?

A). A. No effect on the variable

B). B. SyntaxError is thrown

C). C. Variable value is changed to undefined

D). D. Variable reference is updated

What is the scope of a redeclared variable in JavaScript with let or const?

A). A. Global scope

B). B. Function scope

C). C. Block scope

D). D. Module scope

What is the behavior of a redeclared variable in JavaScript with let or const within nested scopes?

A). A. It inherits the value from the outer scope

B). B. It retains its original value within the nested scope

C). C. It throws an error

D). D. It becomes undefined

How can you avoid accidentally redeclaring variables in JavaScript?

A). A. Always use var for variable declarations

B). B. Use meaningful variable names to avoid conflicts

C). C. Declare variables once and avoid redeclaration

D). D. Use let or const for variable declarations within the same scope

What is the output of the following code snippet?

A). A. SyntaxError is thrown

B). B. 20

C). C. 30

D). D. undefined