What is hoisting in JavaScript?
A). Moving variables to the top of their function or global scope
B). Making variables undefined
C). Creating new variables
D). None of the above
How does block scope help prevent variable hoisting issues?
A). By moving variables to the top of the code
B). By restricting variables to their block
C). By making variables accessible globally
D). By assigning default values to variables
What is the main difference between var and let in terms of scope?
A). var is block-scoped, let is function-scoped
B). var is function-scoped, let is block-scoped
C). Both var and let are block-scoped
D). Both var and let are function-scoped
Which of the following correctly defines a block scope?
A). A scope that encompasses the entire codebase
B). A scope that encompasses a function
C). A scope that encompasses a block of code delimited by curly braces
D). A scope that encompasses an object
What is the output of console.log(outerVar); outside outerFunction if let outerVar = 'Outer'; is declared inside outerFunction?
A). Outer
B). undefined
C). Error
D). null
What is the benefit of block scope in loops?
A). It allows variables to be reassigned within each iteration
B). It prevents variable hoisting
C). It restricts variables to the loop block
D). It makes variables globally accessible
What is the output of console.log(i); outside the loop if let i = 10; is declared inside a loop?
A). 10
B). undefined
C). Error
D). 0
How does block scope affect the visibility of variables in nested blocks?
A). Variables are only visible within their immediate block
B). Variables are visible within all nested blocks
C). Variables are only visible within functions
D). Variables are globally visible
How can you ensure variable immutability within a block?
A). Declare the variable with var
B). Declare the variable with let
C). Declare the variable with const
D). Assign a default value
What is the purpose of block scope in JavaScript?
A). To limit the visibility and accessibility of variables
B). To make variables global
C). To create constants
D). To execute functions