Answer & Solution
Answer: Option C
Solution:
Variables in JavaScript receive an 'Undefined' value when they are declared but not initialized with any specific value.
Q
When does the JavaScript engine assign an 'Undefined' value to a variable?
Related Questions on Average
What does the expression null == undefined return in JavaScript?
A). 1
B). 0
C). undefined
D). null
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.
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 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'.
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'.
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
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.
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.