korstmos

Because paying a few grand a year for a certificate somehow makes your software more trustworthy

What if there are no crappier cars on the road?

Every book has a unique number used to identify them, the ISBN (International Standard Book Number). If you can figure out the ISBN of a book, it becomes an easy search term for piracy, because now you aren’t looking for a long title, you’re looking for a unique number!
Most bookstores will list the ISBN of a book on their website, so that step should be pretty easy.

Then to commit the piracy, you can often just google the ISBN + filetype:pdf and get a free PDF pretty frequently.
There is also library genesis (libgen), where you can look up pirated books via their ISBN, which has a super wide selection.
And if even libgen does not have it, you can try torrent trackers (read up more on !piracy )

Of course most of those options are legally questionable or illegal depending on where you live, and I of course would not recommend you actually perform them ;)

I like how textbooks all have ISBNs
They make pirating them so much easier!

Because even a long (64-bit int) is too small :)
A long can hold 2^64-1 = 1.84E19
A double can hold 1.79E308

Double does some black magic with an exponent, and can hold absolutely massive numbers!

Double also has some situations that it defines as “infinity”, a concept that does not exist in long as far as I know (?)

A BigDecimal?

Doubles have a much higher max value than ints, so if the method were to convert all doubles to ints they would not work for double values above 2^31-1.

(It would work, but any value over 2^31-1 passed to such a function would get clamped to 2^31-1)