var can create a global variable when declared outside any function. let and const do not create global object properties.
What is the global object in a browser environment?
A). window
B). global
C). document
D). this
What is the purpose of the global object in JavaScript?
A). To store local variables
B). To provide a namespace for global variables and functions
C). To define constants
D). To execute code in strict mode
Which of the following methods can help in avoiding global variables?
A). Using functions to encapsulate code
B). Using objects to namespace code
C). Using ES6 modules
D). All of the above
What happens if you declare a variable without var, let, or const inside a function?
A). It becomes a global variable
B). It becomes a local variable
C). It throws an error
D). It becomes a constant
Which keyword is used to declare a variable in the global scope?
A). let
B). var
C). const
D). function
What keyword is used to ensure a variable is block-scoped?
A). var
B). global
C). let
D). window
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
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
In Node.js, what is the global object called?
A). window
B). global
C). document
D). process
What is the output of console.log(window.globalLet); if let globalLet = 'Hello'; is declared in the global scope?
A). Hello
B). undefined
C). error
D). null