Taking Advantage of Locale Independence

In versions of PHP prior to PHP 8, several string functions and operations were tied to the locale. The net effect was that numbers were internally stored differently depending on the locale. This practice introduced subtle inconsistencies that were extremely difficult to detect.

Understanding the problems associated with locale dependence

The unfortunate side effect of locale dependence in earlier PHP versions was inconsistent results when typecasting from float to string and then back again. Inconsistencies were also seen when a float value was concatenated to a string. Certain optimizing operations performed by OpCache resulted in the concatenation operation occurring before the locale had been set, yet another way in which inconsistent results might be produced.