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

Answer & Solution

Answer: Option C
Solution:
When attempting to access a variable that has not been declared, JavaScript returns 'undefined' as the result of the expression 'typeof undefinedVariable'.
Related Questions on Average

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.

Which of the following is an example of using 'Null' in JavaScript?

A). let user = null;

B). let user = undefined;

C). let user;

D). let user = '';

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'.

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'.

Which of the following is a valid use case for 'Null' in JavaScript?

A). Storing default values in variables.

B). Clearing or resetting object references.

C). Assigning placeholders in arrays.

D). Checking if a variable exists.

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.

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.

What does the expression null == undefined return in JavaScript?

A). 1

B). 0

C). undefined

D). null

How do you check if a variable has an 'Undefined' value in JavaScript?

A). Using the undefined keyword.

B). Using the null keyword.

C). Using the typeof operator.

D). Using the empty keyword.

Which of the following statements is true regarding the behavior of 'Undefined' and 'Null' in JavaScript?

A). Undefined and Null are both falsy values in JavaScript.

B). Undefined and Null are both truthy values in JavaScript.

C). Undefined and Null have the same data type in JavaScript.

D). Undefined and Null cannot be compared in JavaScript.