A Guide to Naming Variables

Post by kazinator » Fri, May 13, 2016, 5:45 PM UTC

mixmastamyk wrote: post #32

A good guide, but I didn't like this part: Avoid Over-used Cliches In addition to not being Teutonic, the following variable names have been so horribly abused over the years that they should never be used, ever. val, value result, res, retval tmp, temp count str Cliches? If you are trying to communicate, these names are well known ways to do that. If there is something more specific to put in there, by all means, bu…

Post by krinchan » Fri, May 13, 2016, 5:51 PM UTC

rectang wrote: post #4

Most of this, even if it's not my preference, I would never bother arguing with. But I have a question about a practice that is tremendously widespread. I have real trouble with single-letter variable names like "c", for any function more than, say, 2-3 lines. I scan the code and it increases my mental load because I have to remind myself what it means. Obviously a lot of people don't have problems with this, but I d…

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Post by kps » Fri, May 13, 2016, 6:05 PM UTC

ChuckMcM wrote: post #65

wyldfire wrote: post #61

> iterating through a for loop using i is a well-established idiom that everyone instantly understands. Give that count was useless anyway, i is preferable since it saves 4 characters. "Where does this idiom come from?" you might ask. Well, if I recall it's mostly due to languages like Fortran which implicitly typed identifiers starting with I through N as integers.

exactly right. Some jokes about writing fortran in any language focus on the use of "I, J, and K" as indexes and counters. But in mathematics the common iterator in a summation is also i, j, and k so mathematicians sometimes claim ownership of the use of i as a count.

Post by seanc722 » Fri, May 13, 2016, 6:10 PM UTC

munificent wrote: post #130

philwelch wrote: post #101

Earlier quoted context omitted.

Yeah, the problem with outlawing "retval" in particular is that there's no good variable name in this situation: int sum(Collection c) { int retval = 0; for(int i = 0; i What the hell should I call retval? If I call it sum, that's redundant with the method name. Also, while it might work in Java, it would be more dangerous in a language like Ruby where the equivalent code: def sum(c) sum = 0 c.each do |e| retval += e…

Call it "result": - "val" in "retval" carries no meaning. Everything stored in a variable is a value. - "ret" is an annoying abbreviation for "return" that makes it harder read. - "return" focuses on an implementation detail—that the function produces its value using the language's "return" statement. It doesn't matter how the result is emitted, just that it is. If a function is simple enough that the variable storin…

Post by jdmichal » Fri, May 13, 2016, 6:33 PM UTC

chriswarbo wrote: post #111

elishacook wrote: post #29

Earlier quoted context omitted.

I agree. It's not a mental tax to read a word we recognize. It's not like we have to sound it out letter by letter, we recognize its form at a glance. It's more taxing to maintain a mapping for an inherently meaningless single character. Although there are some single characters that do have meaning due to long time convention such as 'i'.

What about variables which are inherently "meaningless", i.e. they're only given a name in order to distinguish them from each other? For example: function flip(func) { return function(x, y) { return func(y, x); }; } function compose(func1, func2) { return function(x) { return func1(func2(x)); }; } Code like this is completely generic; we know absolutely nothing about `x`, `y`, etc. other than they're distinct argume…

    function compose(f, g) {
        return function (x) {
            return f(g(x));
        };
    }