var outside of any function declares a global variable, whereas let and const do not create properties on the global object.
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
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
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
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 be used to prevent accidental modification of global variables?
A). Encapsulation
B). Namespace
C). Strict mode
D). Block scoping
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 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