Q
Which statement is true regarding the use of 'Undefined'?

Answer & Solution

Answer: Option B
Solution:
Using 'Undefined' to represent missing or uninitialized values is discouraged as it can lead to unexpected behavior and is often considered a mistake in programming.
Related Questions on Average

What does the expression typeof null return in JavaScript?

A). null

B). object

C). undefined

D). function

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.

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.

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.

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.

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'.

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

A). 1

B). 0

C). undefined

D). null

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 = '';

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 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.