# Difference between revisions of "Talk:1537: Types"

Are (6) and (7) about completing sequences?

If the sequence was [1, 2, 3, ?] we would expect the ? to be a placeholder for 4. So [1, 2, 3]+2 is wrong := FALSE. But [1, 2, 3]+4 is correct := TRUE. 141.101.99.22 (talk) (please sign your comments with ~~~~)

"+2 appears to be applying a unary + to the number 2" : or it adds the number of the line, 10, to 2 => 12. Also, the eleventh line, "2+2" may add 2 to all the following 2, explaining line 12. (that theory is from a friend of mine) Seipas (talk) 12:17, 12 June 2015 (UTC)

Also, for the lines 6 and 7, the operation "[1,2,3]+x" may add x to the set [1,2,3] and return true if the operation succeeded or false if not. Adding 2 to the set [1,2,3] returns false because 2 is already in [1,2,3]. Seipas (talk) 12:23, 12 June 2015 (UTC)
I thought it was doing element-wise addition and then comparing "[6] > [3,4,5]" (using the line number in the joke, like in line 10). The problem here is that line 6 should return true and line 7 should return false. Rand (talk) 15:46, 13 June 2015 (UTC)

"The ironic thing is that fractions with 2 in the nominator are not the kind of numbers that typically suffer from floating point impreciseness." - This is not technically correct. Should read "fractions with 'power of 2' in the denominator. However, the 3/2 would cause precision errors. 108.162.221.129 (talk) (please sign your comments with ~~~~)

I don't know proper English wording for things, but 3/2=3*2^-1, so it would be represented exactly under IEEE-754 too. 141.101.89.217 13:58, 12 June 2015 (UTC)

Is there more to this comic, a fixed set of rules that can tie all the examples together, or does each line make its own joke independently? 108.162.219.5 12:54, 12 June 2015 (UTC)

"normally"
This would make sense if it was `[] + 2`

It really wouldn't. Javascript returns `"2"` (god knows why) and Python gives an error. Don't really feel like testing many other languages, but I also think it's not really a logical assumption to make at all. Can't think of a reason for `[] + 2` to return `[2]`... ever. It might make a little bit of sense in Randall's oddly typed language, but not in any sane one. --TotempaaltJ (talk) 12:35, 12 June 2015 (UTC)

Javascript first converts `[]` (the empty array) to the empty string (using the rule "stringify each element and join with a comma"), then treats the operation as `"" + 2`, which results in conversion of the other operand to string and then concatenation. 141.101.97.214 12:46, 12 June 2015 (UTC)

line 4: asci code of N + 2 = asci code of P sirKitKat (talk) 13:07, 12 June 2015 (UTC)

My favourite xkcd in a while. =8o) Of the list I got a good laugh out of numbers 8 and 13. Jarod997 (talk) 13:11, 12 June 2015 (UTC)

I think a lot of this is his joke about programming languages loving the number 4. 2 + "2" = "4", [1,2,3] + 4 = true, 2+2 = DONE, and the range one all seem to support this. Also reminds me of this: http://xkcd.com/221/ 173.245.52.112 (talk) (please sign your comments with ~~~~)

Why isn't yellowish blue just green? Djbrasier (talk) 16:18, 12 June 2015 (UTC)

Because yellow and blue don't make green. 108.162.237.158 23:33, 12 June 2015 (UTC)
It does with my paint kit. Isn't that subtractive mixing. I feel like I've just traveled to a version of 1268: Alternate Universe, except I'm the only one here who went to kindergarten. What am I missing? Djbrasier (talk) 02:28, 13 June 2015 (UTC)
Since this is a Programming language, it must be talking about RGB colors, where green is a base color and yellow is mixed using red and green. So a "yellowish blue" would contain all base colors, resulting in white – and that's propably why Randall's language returns NaN.141.101.92.42 08:39, 13 June 2015 (UTC)
The only color wheel I know has purple (not blue) opposite yellow and orange (not yellow) opposite blue. If that is incorrect, then wikipedia needs some serious editing. Djbrasier (talk) 02:31, 13 June 2015 (UTC)

line 4: I read NaP as Not a Problem. 141.101.104.12 17:00, 12 June 2015 (UTC)

So did I. Xynariz (talk) 23:12, 12 June 2015 (UTC)
To me, the (2/0) looks like a person curled up on bed with the +2 as the Z's indicating sleeping which I believe was the intention on top of 'P' being 2 chars more than 'N'

Line 3 is missing its prompt. There does not appear to be any relevance to the joke, nor has anyone yet explained why it should be missing. Typo? 108.162.221.183 17:10, 12 June 2015 (UTC)

I haven't noticed it until I saw your comment. It seems deliberate to me. Hard not to notice that when writing the fourth line. 108.162.221.48 19:24, 13 June 2015 (UTC)BK201

Note that some programming languages avoid the problem of overloaded '+' operator between operands of vividly different types by using other symbols for string concatenation (be it "a"~"b" or "a"."b") and numerical addition. The real WTF is abusing '+' for string concatenation, which has very different properties from numerical addition, not being symmetrical for example: concat("aa", "bb") == "aabb", while concat("bb", "aa") == "bbaa" != "aabb". --JakubNarebski (talk) 17:38, 12 June 2015 (UTC)

Series of comics? I don't recall any others about Randall's new programming language... 141.101.98.29 19:13, 12 June 2015 (UTC)

+2

I think this is a japanese language joke. The + sign can also refer to the kanji 十, which is 10 in japanese. This would explain the result being twelve. 十二, or 10 2, is twelve in japanese. -- Rafaeladson (talk) (please sign your comments with ~~~~)

I think number 5 is an escaped quote (two consecutive double quotes yields one double quote), a plus sign, and another escaped quote. The result is shown with an alternate form of escaped quotes (the apostrophe and double quote can both be used to show a string). NSIS scripting language uses this notation.108.162.221.180 20:19, 12 June 2015 (UTC)

Clearly this is what the xkcd phone's OS is written in (with some help from StackOverflow) 162.158.68.113 (talk) (please sign your comments with ~~~~)

Great job at explaining the outputs. I clearly would have missed some interpretations without your insights. 108.162.254.146 21:10, 12 June 2015 (UTC)

The joke on line [10] really doesn't seem to be a Chinese/Japanese language joke. We can see that the language interacts much more directly with line numbers from the inter-line joke between lines [11] and [14], where line [12] becomes [14] because the value of 2 has become 4. This is provable by observing that the line after [14] is [13], showing that the previous line really is still line [12], it simply displays as [14] because the value of 2 has changed. This absurdly direct interaction between the code and its line number makes the joke on line [10] make a lot more sense, as a Chinese/Japanese language joke here seems much too contrived and out-of-place considering the nature of the other jokes in the comic. Not to mention, if the joke on line [10] was really concerning the code's interaction with its line number, it would set up nicely for introducing the inter-line joke between lines [11] and [14].188.114.106.89 03:35, 13 June 2015 (UTC)

As a speaker of Japanese, the explanation "[In the Japanese number system] the plus sign is instead the symbol 十" sounds even more absurd than if someone said that English speakers use the small letter "t" as an addition symbol. "十" (ten) and "＋" (full-width plus) are different glyphs and using them interchangeably would certainly not be useful. Although depending on language skill and display font they may visually seem more equal than they're supposed to. 08:28, 13 June 2015 (UTC)

• #5—I'm surprised we've missed the obvious joke: quotations within quotations. the double-quatation "I think so." gets single-quoted within another quotation: "He said, 'I think so.'"
• The word is "complements", not "opposites", on the colour wheel. I think the joke is likely that most people think of "yellowish blue" as "green"—as it would be on an artists' colour wheel. Regardless, complements on an RGB colour wheel should not result in NaN—it would result in a mix of yellow (255, 255, 0) and blue (0, 0, 255), which is white (255, 255, 255).
• 108.162.226.174 12:23, 13 June 2015 (UTC)