What is the difference between "Undefined" and "Null" in JavaScript?

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 the JavaScript engine assign an 'Undefined' value to a variable?

A). When the variable is intentionally set to 'Undefined'.

B). When the variable is not declared but used.

C). When the variable is declared but not initialized.

D). When the variable is initialized with the value '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'.

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 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.

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 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.

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

A). object

B). function

C). undefined

D). null

What does the expression typeof null return in JavaScript?

A). null

B). object

C). undefined

D). function