Foundations - C173 Questions
with Accurate Answers
- correct answer subtract
* correct answer multiply
/ correct answer divide
% correct answer Modulos, does division and returns the remainder
+ correct answer concatenate or add
< correct answer less than
<= correct answer less than or equal to
= correct answer assignment
== correct answer comparisons equality
> correct answer greater than
,>= correct answer greater than or equal to
Boolean is a true or false value correct answer example: myVar = True
How are buckets used in a hash table? What effect do they have on lookup
speed? correct answer Entries in a hash table are mapped to a number, which is
the position in the index where you should look for the entry. A hash table has
numbered bucket slots that hold entries. The entries are organized in the buckets
based on their assigned keyword number. When you run a search using a hash
table the keyword assigned will be used to determine which bucket the entry
should be located in and begin the search there. Because the search knows where
to begin looking it is much quicker to look up items.
How are compound mathematical expressions evaluated in Python? correct
answer First perform calculations within parentheses.
Next work left to right and perform all multiplication and division.
Finally, work left to right and perform all addition and subtraction
How are elements in a list indexed? correct answer List elements are assigned an
index number starting with 0.
How do you change the value of a variable with Python? correct answer Using the
= character to assign a new value
x=6
x=9
print x # would print out 9
, How do you define outputs for a function? correct answer Using the return
keyword you can define what data will be returned or output when the procedure
or function runs. You can only access data from within a function if you return
that specific data to be used outside of the function.
How do you prioritize case (best case, worst case, average case) when analyzing
algorithms? correct answer You would look at them in this order: Worst case,
average case, best case. The worst case is the most important because this will
give you a better understanding of why the time scales as it does.
How do you select a sub-sequence of a list with Python? correct answer You
specify the index position to begin the selection and the index position by which
to stop the selection. For example, the following code would print red and yellow
because they are at position 0 and 1.The value of 2 tells us to stop the selection at
position 2, but not to include it.
myColors = ["red","yellow","blue","orange","green"]
print myColors[0:2]
How do you update a list item with Python? correct answer By specifying the
element that you want to update and then assigning a new value. For example,
the following code would change the second element in list, from yellow to
purple.
myColors = ["red","yellow","blue","orange","green"]
myColors[1] = "purple"
print myColors