Answer & Solution
let keyword is used to declare block-scoped variables.
let keyword is used to declare block-scoped variables.
What is the output of typeof window in a browser environment?
A). object
B). undefined
C). function
D). global
How do you declare a global variable inside a function?
A). Using var
B). Using let
C). Using const
D). Assigning to window
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
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 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
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 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
Which of the following can be used to prevent accidental modification of global variables?
A). Encapsulation
B). Namespace
C). Strict mode
D). Block scoping
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