Answer & Solution
window
, e.g., window.myVar = 'value';
window
, e.g., window.myVar = 'value';
Which of the following can create a global variable?
A). var
B). let
C). const
D). All of the above
Can global variables lead to name collisions in large codebases?
A). Yes
B). No
C). Only if not managed properly
D). Only in strict mode
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 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 happens if you declare a variable inside a function with the same name as a global variable?
A). It creates a new local variable
B). It throws an error
C). It modifies the global variable
D). It assigns the global variable to 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
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 is the output of console.log(globalThis === window);
in a browser environment?
A). 1
B). 0
C). undefined
D). null
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 is the output of typeof window
in a browser environment?
A). object
B). undefined
C). function
D). global