Translations:Extension:Scribunto/Lua reference manual/1291/en

Note that all numbers (including 0, NaN, and infinities) are considered true when converted to boolean. This is unlike most other languages, where the number 0 is usually considered false. When converted to a string, finite numbers are represented in decimal, possibly in E notation; NaN is $nan or $-nan; and infinities are $inf or $-inf.