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 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 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 of the following scenarios is a common cause of variables having an 'Undefined' value?
A). When variables are explicitly set to 'Undefined'.
B). When variables are declared but not initialized.
C). When variables are intentionally set to 'Null'.
D). When variables are assigned default values.
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.
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'.
What does the expression null == undefined return in JavaScript?
A). 1
B). 0
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'.
What is the result of the expression typeof undefinedVariable if undefinedVariable is not declared?
A). object
B). function
C). undefined
D). null
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.