This lab is due by Thursday, June 6, 2019, 11:59 PM.
As with all labs you may, and are encouraged, to pair program a solution to this lab.
Concepts
This assignment introduces you to a
simple form of "unit testing" as a mechanism for exploring the string
API. Focus on learning what unit tests are, what an "API" is, and what
you can do with string objects.
APIs (Application Programming Interface)
As you can see above, the acronym API stands for Application
Programming Interface. But what does that mean? In a nutshell,
an API describes what you can do with a particular library or object
that you are provided (or that you create). It describes how your code
can "interface with" or "use" a particular library or object.
For example, the string API consists
of member functions that tell you how long the string is, allow you to
capitalize the string, tell you whether it contains a specific
character, or allow you to extract a part of the string.
While the API really is the programmatic components that you can
actually use, we often rely on API documentation to discover
what you can do with a particular library or object. For example, in
this assignment you will use the string API, and you will need
to look up some API documentation about how you can use string objects.
Unit Testing
As entire books have been written on
unit testing, we will merely introduce the topic here. A "unit test" is
a small piece of code designed to test a specific part of a program's
functionality. In other words, they are bits of code that test the
functionality of other code!
For this assignment, that's all the
preliminary information you really need to know about unit testing. You
will actually write the unit tests, eventually getting the entire test
suite to pass (at which point you should go outside and run a victory
lap).
The
string
Mantra
How you read and interpret
object-oriented code is important when it comes to understanding the
difference between data types, variables, and the "values" that a
variable represents. Take a look at the following code.
string name = "Jimi Hendrix";
You are familiar with that syntax, but
as we delve into objects we want to emphasize a particular way of
translating that from "computerese" to English. When reading the above
code, you should say to yourself "name is a string whose contents are
the words Jimi Hendrix." Say that sentence aloud while reading the line
of code above. Seriously, say it aloud about three or four times:
"name is a string whose contents are
the words Jimi Hendrix. name is a string whose contents are the words
Jimi Hendrix. name is a string whose contents are the words Jimi
Hendrix. name is a string whose contents are the words Jimi Hendrix."
Doing this will help hammer home the
way you should translate this line of code (and make anyone near you
think there is something seriously wrong with you).
Instructions
A skeletal test suite (a collection of functions) has been provided for
you in
StringTests_main.cpp.
Notice that the functions in this code are defined below
main.cpp. In this case, each
function is performming a single test on a string. The function will
need to return the result of the test.
Your job: complete the function implementations using the string API
such that all tests pass. You should not modify the contents of
main
in this lab, and instead only implement the test functions.
You should start by reading the body of the function called
runAllTests()
in order to see what your functions must accomplish. For example, the
function
stringLength()
must return the length of the string "Now" using the string API. Take a
look at the function
stringLength()
to see an example of a successful implementation.
When your program prints "PASSED" for
a given unit test instead of "FAILED," then you know that your function
implementation for that test is complete. Once you get all functions to
print "PASSED", do your victory lap!
Hints
- We recommend that you complete the functions in the order in which
they are called in
runAllTests(). - If you have trouble getting a function to pass its test, use the debugger with breakpoints to help you troubleshoot what your code is doing.
- Leverage the string API as much as you can. Explore the string API to see how the functions work. The documentation may be somewhat confusing; thus, if there is something you don't understand, be sure to ask!
Functional Requirements
- You must not modify the contents of
main()orrunAllTests().
Lab Submission
You will submit your solution to this lab with the rest of Set6. Detailed instructions for doing this are posted in Assignment 6.
This lab is due by Thursday, June 6, 2019, 11:59 PM.
As with all labs you may, and are encouraged, to pair program a solution to this lab.