var outside of any function declares a global variable, whereas let and const do not create properties on the global object.
What is the output of typeof window in a browser environment?
A). object
B). undefined
C). function
D). global
How can you access a global variable inside a function if it has the same name as a local variable?
A). By using the window object
B). By using the global object
C). By using a different name for the global variable
D). By using the this keyword
Can a global variable be accessed inside a function?
A). Yes
B). No
C). Only if passed as a parameter
D). Only if defined with var
What keyword is used to ensure a variable is block-scoped?
A). var
B). global
C). let
D). window
What is the output of console.log(globalThis === window); in a browser environment?
A). 1
B). 0
C). undefined
D). null
Which of the following can create a global variable?
A). var
B). let
C). const
D). All of the above
What is the output of console.log(globalVar); if globalVar = 'Hello'; is assigned inside a function without using var, let, or const?
A). Hello
B). undefined
C). error
D). null
How can you avoid global scope pollution?
A). By using local variables
B). By using IIFE (Immediately Invoked Function Expressions)
C). By using modules
D). All of the above
Which of the following can be used to prevent accidental modification of global variables?
A). Encapsulation
B). Namespace
C). Strict mode
D). Block scoping
What will be the output of console.log(window.myVar); if var myVar = 'Hello'; is declared outside any function?
A). Hello
B). undefined
C). error
D). null