Q
What does the expression typeof null return in JavaScript?

Answer & Solution

Answer: Option B
Solution:
Although 'Null' is a distinct primitive data type in JavaScript, the expression typeof null returns 'object' due to a historical quirk or bug in JavaScript.
Related Questions on Average

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.

Which of the following correctly describes the purpose of 'Null' in JavaScript?

A). Null is used to represent an empty array.

B). Null is used to indicate that a variable is uninitialized.

C). Null is used to represent an intentional absence of value.

D). Null is used to check for object properties.

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'.

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.

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 is the result of the expression typeof undefinedVariable if undefinedVariable is not declared?

A). object

B). function

C). undefined

D). null

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.

Which of the following statements is correct regarding the comparison of 'Undefined' and 'Null'?

A). Undefined and Null are strictly equal in JavaScript.

B). Undefined and Null are not strictly equal in JavaScript.

C). Undefined is considered a subtype of Null.

D). Null is considered a subtype of Undefined.

How is 'Null' different from 'Undefined'?

A). Null represents variables that have been initialized but not declared.

B). Null represents an intentional absence of value or object reference.

C). Null is never used in programming.

D). Null is a substitute for 'Undefined'.