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.
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.
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.
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.
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 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 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.
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'.
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.