Answer & Solution
Answer: Option C
Solution:
Variables have an 'Undefined' value when they are declared but not initialized, meaning they exist in memory but haven't been given a specific value yet.
Q
When does a variable typically have an 'Undefined' value?
Related Questions on Average
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'.
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 = '';
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'.
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 does the expression typeof null return in JavaScript?
A). null
B). object
C). undefined
D). function
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.
What is the result of the expression typeof undefinedVariable if undefinedVariable is not declared?
A). object
B). function
C). undefined
D). null
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 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 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.