Functions affected by locale in PHP

A problem occurs in the project. Different servers have different running results.

The reason is that some functions related to locale are used and the server locale is different. These functions are summarized as follows:

String:

Strtoupper	Convert uppercase letters
Strtolower	Convert lowercase letters
Ucfirst	Uppercase letters
Sprintf	Some formatting is related
Ctype_alpha	Check whether all letters exist
Ctype_alnum	Check whether all numbers exist.
Ctype_cntrl	Check whether all characters are controlled
Ctype_upper	Check whether all uppercase letters are used
Ctype_lower	Check whether all lowercase letters are used

Date-related:

Gmstrftime	Format GMT/UTC time/date according to region settings
Strftime	Format local time/date according to region settings
Strptime	The time returned by strftime processing is an array.

Currency:

Money_format

Format the number in currency format

Finally, there are locale related functions:

Setlocale	Set local
Localeconv	Obtain digit-related locale information

As a domestic phper, it is inevitable to encounter many problems related to locale. At this time, it is best to use the MB _ * series functions and clearly specify the relevant character set to avoid these problems.