Answer & Solution
globalThis
refers to the global object, which is window
. Hence, the output is true
.
console.log(globalThis === window);
in a browser environment?
globalThis
refers to the global object, which is window
. Hence, the output is true
.
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
Which statement is true about global variables in JavaScript?
A). They are not accessible inside functions
B). They can be accessed and modified from any part of the code
C). They are constants
D). They can only be read, not modified
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
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 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
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 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
What keyword is used to ensure a variable is block-scoped?
A). var
B). global
C). let
D). window
How do you declare a global variable inside a function?
A). Using var
B). Using let
C). Using const
D). Assigning to window