Which statement best describes the relationship between 'Undefined' and 'Null' in JavaScript?
A). Undefined and Null are interchangeable and can be used interchangeably in code.
B). Undefined and Null are distinct values representing different states in JavaScript.
C). Undefined is a subset of Null, encompassing all possible values of Null.
D). Null is a subset of Undefined, encompassing all possible values of Undefined.
What does the expression null == undefined return in JavaScript?
A). 1
B). 0
C). undefined
D). null
What is the purpose of using 'Null' over 'Undefined' in certain programming scenarios?
A). To represent an intentional absence of value or object reference.
B). To assign default values to variables.
C). To represent uninitialized variables.
D). To check for variable existence.
What happens when a function does not explicitly return a value in JavaScript?
A). It returns 'null'.
B). It returns 'undefined'.
C). It throws an error.
D). It returns 'object'.
What is the difference between 'Undefined' and 'Null' in JavaScript?
A). Undefined is a value, while Null is an absence of value.
B). Undefined is an absence of value, while Null is a value.
C). Undefined is never intentional, while Null is always intentional.
D). Undefined is always intentional, while Null is never intentional.
Which statement is true regarding the use of 'Undefined'?
A). Undefined is commonly used to reset variables in loops.
B). Undefined is generally avoided and considered a programming error.
C). Undefined is used to represent empty strings.
D). Undefined is only used in function declarations.
When does a variable typically have an 'Undefined' value?
A). When it is intentionally set to represent no value.
B). When it is assigned a default value.
C). When it is declared but not initialized.
D). When it is explicitly set to 'Undefined'.
Which of the following scenarios is a common cause of variables having an 'Undefined' value?
A). When variables are explicitly set to 'Undefined'.
B). When variables are declared but not initialized.
C). When variables are intentionally set to 'Null'.
D). When variables are assigned default values.
How does the typeof operator behave when applied to an 'Undefined' value?
A). It returns 'undefined'.
B). It returns 'null'.
C). It throws an error.
D). It returns 'object'.
How do you assign a variable to have a value of 'Null'?
A). Using the assignment operator =.
B). Using the null keyword.
C). Using the undefined keyword.
D). Using the void operator.