In this case, alpha is an abbreviation for alphabetic. The passage is telling us that the
DAYNAME function returns an value (answer) consisting only of letters (alpha), rather than a numerical indicator, which is what
The use of the term alpha answer is not standard English at all. Even in the realm of programming jargon, it's not correct. Though we can determine the meaning from the context, alpha by itself is ambiguous as an abbreviation. It can mean either alphabetic or alphanumeric, both of which are frequently used when talking about strings. Also, answer is the wrong word (even colloquially) for referring to the result yielded by a function. The correct term is return value (often shortened to just value).
In addition to misusing the terms, the sentence containing an alpha answer is semantically wrong. The answer is what's returned, but it's being used as the subject of the sentence when it should be an object. As written, the sentence means the answer is what's doing the returning. This is wrong because the return value is just a value; it doesn't do anything. It's the function that returns something.
Here's how it should be written:
As you can see, the function returns an alphabetic value: