Instructions

A specification is a formal statement about program behavior. A temporal property is a kind of specification that constraints the sequence of events that can or cannot occur on a single instance during an execution of a program.
An example of a true temporal property: close() is always preceded by open(). This property is true because to close a file the file must first be open (otherwise there is an error).
An example of a false temporal property: open() is always followed by close(). This property is false because an error does not necessarily occur if close() is not called after open(), even if it is good programming practice to do so. Note that a property is true ONLY IF a program that does not not follow the property constraint may results in an error (e.g., an Exception in Java) or the violation will never happen in the program.
Questions in the table are used to test your understanding of these instructions and the APIs. You must pass the qualification test to complete the HITs in this group. You will pass the test if you correctly answer over 5 out of 7 questions in the table.
You must answer all questions. A good faith effort is required for payment.

Examples	Tests
Example 1. In HashMap library, HashMap() always precedes size() Correct answer: True Explanation:HashMap() is a constructor, which should be called before any method for a certain object.	Test 1. In ArrayList library, ArrayList() always precedes clear()* True False
Example 2. In HashMap library, remove() is never followed by HashMap() Correct answer: True Explanation:HashMap() is a constructor, which should be called before any method for a certain object. Thus, its appearance will not follow other methods.	Test 2. In ArrayList library, clone() is always followed by ArrayList()* True False
Example 3. In HashMap library, remove() is never immediately followed by HashMap() Correct answer: True Explanation:HashMap() is a constructor, which should be called before any method for a certain object. Thus, its appearance will not follow other methods.	Test 3. In ArrayList library, contain()=True is never immediately followed by ArrayList()* True False
Example 4. In HashMap library, isEmpty()=False is never immediately followed by isEmpty()=True Correct answer: True Explanation:A not empty HashMap object could not be empty without any operation followed. This will not result in an error since it will never happen.	Test 4. In ArrayList library, isEmpty()=False is always immediately followed by isEmpty()=True* True False
Example 5. In HashMap library, HashMap() always immediately precedes size() Correct answer: False Explanation:After calling constructor, we could call methods like put(), putAll(), isEmpty() et al. before calling size().	Test 5. In ArrayList library, HashMap() always immediately precedes size()* True False
Example 6. In HashMap library, put() is always followed by size() Correct answer: False Explanation:For a HashMap object we can always add something by calling put() without followed by calling method size(), this would not incur any error in program.	Test 6. In ArrayList library, remove()=False is always immediately followed by clone()* True False
Example 7. In HashMap library, remove() is always immediately followed by size() Correct answer: False Explanation:Method remove() could be immediately followed by methods like put(), putAll(), isEmpty() et al. There is no error to call remove() first then immediately call put().	Test 7. In ArrayList library, toArray() is always immediately followed by listIterator()* True False

Examples

Tests

Example 1. In HashMap library, HashMap() always precedes size()

Correct answer: True

Explanation:HashMap() is a constructor, which should be called before any method for a certain object.

Test 1. In ArrayList library, ArrayList() always precedes clear()*

True

False

Example 2. In HashMap library, remove() is never followed by HashMap()

Correct answer: True

Explanation:HashMap() is a constructor, which should be called before any method for a certain object. Thus, its appearance will not follow other methods.

Test 2. In ArrayList library, clone() is always followed by ArrayList()*

True

False

Example 3. In HashMap library, remove() is never immediately followed by HashMap()

Correct answer: True

Explanation:HashMap() is a constructor, which should be called before any method for a certain object. Thus, its appearance will not follow other methods.

Test 3. In ArrayList library, contain()=True is never immediately followed by ArrayList()*

True

False

Example 4. In HashMap library, isEmpty()=False is never immediately followed by isEmpty()=True

Correct answer: True

Explanation:A not empty HashMap object could not be empty without any operation followed. This will not result in an error since it will never happen.

Test 4. In ArrayList library, isEmpty()=False is always immediately followed by isEmpty()=True*

True

False

Example 5. In HashMap library, HashMap() always immediately precedes size()

Correct answer: False

Explanation:After calling constructor, we could call methods like put(), putAll(), isEmpty() et al. before calling size().

Test 5. In ArrayList library, HashMap() always immediately precedes size()*

True

False

Example 6. In HashMap library, put() is always followed by size()

Correct answer: False

Explanation:For a HashMap object we can always add something by calling put() without followed by calling method size(), this would not incur any error in program.

Test 6. In ArrayList library, remove()=False is always immediately followed by clone()*

True

False

Example 7. In HashMap library, remove() is always immediately followed by size()

Correct answer: False

Explanation:Method remove() could be immediately followed by methods like put(), putAll(), isEmpty() et al. There is no error to call remove() first then immediately call put().

Test 7. In ArrayList library, toArray() is always immediately followed by listIterator()*

True

False

A specification is a formal statement about program behavior. A temporal property is a kind of specification that constraints the sequence of events that can or cannot occur on a single instance during an execution of a program.

An example of a true temporal property: close() is always preceded by open(). This property is true because to close a file the file must first be open (otherwise there is an error).

Questions in the table are used to test your understanding of these instructions and the APIs. You must pass the qualification test to complete the HITs in this group. You will pass the test if you correctly answer over 5 out of 7 questions in the table.

You must answer all questions. A good faith effort is required for payment.