What is the default scope of variables declared with the 'var' keyword in JavaScript?
A). Block scope
B). Function scope
C). Module scope
D). Block and function scope
How do 'var' declarations handle hoisting?
A). They are not hoisted
B). Only the assignment is hoisted
C). Only the declaration is hoisted
D). Both declaration and assignment are hoisted
How does 'let' handle variable re-declaration in the same scope?
A). Allows it
B). Silently ignores
C). Throws an error
D). Creates a new variable
What will be the output of the following code: const z = 30; z = 40; console.log(z);
A). 30
B). 40
C). Error
D). undefined
What will be the output of the following code: const d = 90; d = 100; console.log(d);
A). 90
B). 100
C). Error
D). undefined
Can you re-declare a variable using 'const' in the same scope?
A). Yes
B). No
C). Only in functions
D). Only in loops
Which keyword allows block-scoped variable declaration?
A). var
B). let
C). const
D). Both B and C
What will be the output of the following code: var x = 5; var x = 10; console.log(x);
A). 5
B). 10
C). Error
D). undefined
Which keyword is used for declaring variables that should not change?
A). var
B). let
C). const
D). all of the above
What will be the output of the following code: var e = 110; if (true) { var e = 120; } console.log(e);
A). 110
B). 120
C). Error
D). undefined