The writer most likely count the moslem population. Most moslem don't speak arabic but they recite quran (written in arabic) daily. Most of them will notice if a ال written as ل ا

Egypt has ~100 million people, the vast majority of whom are going to be native Arabic speakers. Algeria, Sudan, and Iraq also have ~40 million people each, again, most of whom are native Arabic speakers (of different varieties). Morocco, Saudi Arabia, and Yemen are no slouches either. In short 300 million native speakers of various Arabic languages is extremely plausible.

FWIW, the usual estimate for worldwide adherents to Islam is ~1 billion.

FWIW, I am not a muslim nor a native Arabic speaker but I "can read the Arabic alphabet to some degree".

Though if your numbers are correct, 2 billion sounds way too high

PEW Research and Wikipedia estimate are 1.9B.

[1] https://www.pewresearch.org/religion/2011/01/27/the-future-o...

[2] https://en.wikipedia.org/wiki/Islam_by_country

Those estimates are not for Arabic readers or speakers. They are for Muslim or Islam.

Arabic is both a (group of) language(s) and an alphabet/script. The page isn't claiming that 2B people speak some dialect of the Arabic language, it is claiming some 2B people have a degree of literacy in the alphabet/script, so a quarter of the world's population will potentially know if you've screwed up your website/app/game/whatever. You don't need to speak Latin to know that "anunmtMh mucjmydDDDDD" is just the result of me mashing random keys on my keyboard, because you can read Latin letters. Likewise no Mongolian speaker would believe "прнтзх йоэЁюи" is proper Russian, even though those two languages are wildly different.

Also I cannot read Arabic and know enough to see that something is wrong if it's LTR.

Now I know:

> 3. In general, the letter combination ال should be common. The combination ل ا cannot occur in Arabic script, as those characters should be connected.

I still cannot read a jot of Arabic and know enough to identify some cases where the dev/writer has gotten it wrong.

Most Muslims are taught how to read Arabic script, even if they can't understand or speak Arabic. That is because reading the Qur'an in its Arabic form, even without understanding, is a sacred act above reading the translation. Additionally, ritual prayers require reciting verses in Arabic, (again without necessarily understanding). Therefore it's not weird to assume the number of people familiar with Arabic script include the population of non-Arabic speaking Muslims.