Editing 1275: int(pi)

{{comic
| number    = 1275
| date      = October 9, 2013
| title     = int(pi)
| image     = int pi.png
| titletext = If replacing all the '3's doesn't fix your code, remove the 4s, too, with 'ceiling(pi) / floor(pi) * pi * r^floor(pi)'. Mmm, floor pie.
}}

==Explanation==
This comic purports to provide a tip to programmers, that the number "{{w|3 (number)|3}}" is cursed and shouldn't be used. There is no explanation given as to why the number 3 is cursed, and it could well have been chosen arbitrarily. The title text hints that the consequence for using the cursed number is non-functioning code, a pain for any programmer. The absurdity of the number 3 somehow being cursed is part of the humor.

To assist the programmer, the comic gives an example of how to avoid the use of the number 3, by using a slightly convoluted method of using <code>int(pi)</code>, which means the {{w|integer}} part of {{w|pi}}, without the {{w|fractional part}}. Pi, an {{w|irrational number}}, has a value starting <code>3.14159...</code>, making <code>int(pi)</code> equal to 3. This is demonstrated in a formula to calculate the {{w|Sphere#Enclosed volume|volume of a sphere}}, normally (4/3)*pi*(r^3), but converted for avoidance of the number 3 to (4/int(pi))*pi*(r^int(pi)).

For a number of reasons it is a good programming practice to use {{w|Variable (computer science)|variables}} and {{w|Constant (programming)|constants}} where a value is used in multiple places, however this is not typically used in the case of natural numbers. There are unusual situations where this type of programming is a valid method, however typically for more specific circumstances, and not a certain number being seen as cursed.

In the title text, Randall takes the joke a step further, suggesting the usage of {{w|floor and ceiling functions}}: <code>ceiling(pi)</code> would be pi rounded ''up'' to the next integer, which is {{w|4 (number)|4}}; and <code>floor(pi)</code> is pi rounded ''down'' to the next integer, which is 3. (Note that <code>int(n)</code> and <code>floor(n)</code> have the same value when <code>n</code> is greater than or equal to zero. For values less than zero, <code>int(n)</code> is equal to <code>ceiling(n)</code>.)

The joke here plays on the fact that basic rules of programming are confusing and novice programmers are often told to simply not do certain things without any explanation (see [[292: goto]]). This includes, in particular, a general proscription against "{{w|Magic number (programming)#Unnamed numerical constants|magic numbers}}" in the code. Replacing all significant magic numbers with named constants makes programs easier to read, understand and maintain. Randall takes this to an extreme by suggesting that certain numbers could be inherently problematic, but the general idea is perfectly believable.

[https://youtube.com/watch?v=MYgchYm0syg ''Mmm... Floor pie.''] is a reference to The Simpsons.

See also {{w|Cargo cult programming}}.

==Transcript==
:[Inside a frame a formula is shown:]
:volume(r) = (4/int(pi))*pi*r^int(pi)

:[Caption below the frame:]
:Programming Tip: The number "3" is cursed. Avoid it.

{{comic discussion}}
[[Category:Programming]]
[[Category:Geometry]]
[[Category:Comics with cursed items]] <!-- The single digit betwixt 2 and 4; One quarter of a dozen; Exactly half the number of toes you should have left if you first cut off one for each arm and leg you possess... -->