Difference between revisions of "PowersOf2Iterable"
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=Testing Your Solution= | =Testing Your Solution= | ||
==Correctness== | ==Correctness== | ||
− | {{TestSuite|_PowersOfTwoTestSuite|powersoftwo.exercise}} | + | {{TestSuite|_PowersOfTwoTestSuite|iteration.powersoftwo.exercise}} |
=Pledge, Acknowledgments, Citations= | =Pledge, Acknowledgments, Citations= | ||
{{Pledge|studio-powers-of-two-iterable}} | {{Pledge|studio-powers-of-two-iterable}} |
Revision as of 16:56, 5 February 2022
Contents
Motivation
- Gain experience with implementing interfaces.
- Build a utility which will come in handy later in the semester (for example, the Scan exercise).
Investigate
interface Iterable<T>
interface Iterator<T>
Mistakes To Avoid
Warning: Do NOT Parallelize |
Warning: Do NOT confuse Iterable<T> from Iterator<T> |
How To Use
for(int v : new PowersOfTwoLessThan(71)) { System.out.println(v); }
should produce the output:
1 2 4 8 16 32 64
Code to Implement
It is important to consider what state each class should encapsulate. The class PowersOfTwoLessThan, which is Iterable, should be have need to store little (if anything) beyond the maxExclusive passed in to its constructor. Further, PowersOfTwoLessThan should be immutable. There is no need to change any of the data during its lifetime.
The Iterator<Integer> instances created whenever one invokes the iterator() method? Now, the data for those instances are going to need to mutate.
One should NOT need to create a List to support this class. A single private final int instance variable is all you need for PowersOfTwoLessThan and a single (mutable) int instance variable is all you need for its Iterator.
class: | PowersOfTwoLessThan.java | |
methods: | constructor iterator |
|
package: | iteration.powersoftwo.exercise | |
source folder: | student/src/main/java |
constructor
constructor: public PowersOfTwoLessThan(int maxExclusive)
iterator
method: public Iterator<Integer> iterator()
(sequential implementation only)
Investigate: Anonymous Inner Classes
Testing Your Solution
Correctness
class: | _PowersOfTwoTestSuite.java | |
package: | iteration.powersoftwo.exercise | |
source folder: | testing/src/test/java |
Pledge, Acknowledgments, Citations
file: | studio-powers-of-two-iterable-pledge-acknowledgments-citations.txt |
More info about the Honor Pledge