JavaScript Standards for IO

Question

When it comes to JavaScript code-golf, there tends to be two schools of thought regarding IO (specifically printing).

Some golfers will use functions such as alert, document.write, and console.log (explicit printing), whereas other golfers will rely on the console implicitly logging the return value of statements executed in it (implicit printing).

I think it's worth discussing what the standard should be so that developers who make use of explicit printing are not at a disadvantage against developers using implicit printing. Of course, anyone posting a code golf could always explicitly override the standard.

Personally I believe that JavaScript code golf should work irrespective of where it's executed* (<script> element, browser console, node, etc), which means that explicit printing would be required.

_{* some golfs will require exceptions to this due to the nature of the different environments}

Answer 1

Here is my proposal for a standard:

• Use alert if the code runs in web browser (for example if it modifies DOM), or just uses core JavaScript (as it's easy to claim it's a browser code in this case). It should be used just once, as message boxes are annoying when shown multiple times (this means you should prepare a buffer for alert).

• You can almost always use console.log. You need to if you work with non-browser environments, such as Node.js. For example, if code uses require in order to load stuff like Underscore.js, it has to use console.log. It's longer than alert however, so it probably won't be used outside of Node.js context.

• Use print if you write code for SpiderMonkey, without web browser. I don't know why you would want to, but you can. Just tell that code requires SpiderMonkey, because web browsers use print for something else (printing on printer, that is).

• Use document.write if you need to output HTML, or want to output in multiple statements, or something. Otherwise, alert is shorter.

• Write a function when task asks you to, and return the value.

• Never use implicit print statement. That's cheating in my opinion, and won't work outside of dev console. If you really want to, make Node.js code, and say it runs with -p. It also would waste 1 character (On "interactive" answers and other special conditions).

Answer 2

I propose we adopt a standard I/O library with published specifications. This allows platforms with different I/O models to use variations of this standard library to just work. I have seen this approach used in textbooks with good results.

Answer 3

I have no idea how that's done in JavaScript, but for multi-language challenges, I don't think it should get any preferential treatment. The common case is “write to stdout”, and it should stick to that unless specifically allowed by the problem.