I’m working on a problem for a programming class that states the following:
Write a for loop in the space below which will add the numbers between 1 and 20.
To me this means the question is looking for the total sum of all the individual numbers from 1 up to 20 (1 + 2 + 3 + 4 + 5 + … + 20).
Is my understanding correct?
Are there any other ways to word this?
As a programmer, every usage of the between keyword I've seen would define 'between X and Y' as 'greater than or equal to X and less than or equal to Y'
An example would be the BETWEEN comparison operator in MySQL.
I would say your interpretation of 'between 1 and 20' to include the upper and lower bounds (1 and 20) is absolutely correct.
Having said that, it could certainly be more clearly worded. For starters, adding 'the numbers' between 1 and 20, or even 1 and 1.000000001, would be an endless task. They should specify integers at the very least, as well as using a less ambiguous definition of the boundaries such as suggested by @MetaEd (+1).
In the context of a programming class, it is particularly important to avoid ambiguity about the input. In this case, between could mean the numbers 2 through 19. Perhaps try
… which computes the sum of the numbers 1 through 20.
I imagine that you're interpreting it the way it was intended, but it should have been worded more clearly. Perhaps "add the integers from 1 through 20, inclusive."
Since it's a relatively ambiguous question that you have to solve, the appropriate thing to do is comment your code with your assumptions. In general, commenting ambiguity, or anywhere where you have questions, is best practice.
Here, the ambiguity is the range of numbers. Is it [1,20], i.e. inclusive? (Probably.) But it could also be (1,20) (exclusive), or a mix, e.g. [1,20). In fact, many loop or range functionalities expect an input of the form [x,y)!
Ambiguity? Comment the shit out of it, if you'll pardon my segue to french.SE!
If you get the code and your assumptions right, then you have clean, clear code and you'll be making best practice into routine. Programmers will love you forever if you comment your code. We almost don't care about it working, by comparison, as long as there's some English there so we can follow your lead.
If your answer isn't what is expected, many courses will hand the code off to grad students to look at. If your comments detail your work so that they can understand it, and your code did what you thought it did, you often get at least some credit. This means that if your code is right but your assumptions are wrong, you're only faulted on your assumptions, and you get credit for writing code that does what you want.
...will add the integers [1,20], which unambiguously states that the range is inclusive of 1 and 20.