No, we don’t have four i’s in Turkish. I(ı) and İ(i) are two separate letters. Turkish alphabet has 29 letters, and each letter has their own key on a Turkish keyboard. We also have Öö, Üü, Çç, Şş and Ğğ. These are all individual letters. They are not dotted versions, accents or a writing convention. So the language is as simple as it gets. The complications come from mapping letters to English alphabet.
other languages are hit by the same hard destiny.
German language has öäüÖÄÜ and ßẞ, yet typographically, the only "real" letter of these is ßẞ, the others are "Umlaut" aouAOU.
Linguistically they are "letters" of their own right. With obscure rules for sorting and capitalization, especially if the typeface doesn't have capital ÄÖÜẞ. then they become what they were AE, OE, UE, SZ...
and that's what the article is about: locale matters.
and in that context you have four i-like glyphs in tr-TR. and if you do anything locale sensitive in your code, like case folding, better set the locale explicitly...
(I guess that when it was made, more than one hundred years ago, it didn't seem that bad)
It can't just be "i", there would only be one glyph then.
But if we're calling multiple things "i's", I think it's reasonable to include all four.
1. i
2. I
> No, we don’t have four i’s in Turkish. I(ı) and İ(i) are two separate letters
1. ı
2. I
3. i
4. İ
--> 4
There was a great article posted here not too long ago about the actual origin of the qwerty keyboard, spoiler, it was not actually designed to slow typing down. Anyway a fun fact found in that article was why "I" is where it is. An early adopter of the typewriter was a telegraph transcription company. and they wanted "I" moved near the end of the numbers so using it as a "1" they could type the 18 in 1875 quicker.
https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433...
So while we have two i's, they have four
1. i
2. I
No, we don't have four i's in English, I(i) and J(j) are two separate letters
1. i
2. I
3. j
4. J
--> 4