Using the PHP Function Mb_StrtoUper() and Mb_Strcpl()

PHP functions are a key part of the programming language, allowing you to encapsulate a group of statements together in one self-contained unit. This helps to keep your code organized, efficient and modular. The use of functions can also help to improve code readability and comprehension.

When writing a PHP program, it is often necessary to convert string data into different cases. There are several functions available for this purpose including strtolower(), strtoupper() and mb_strtoupper().

The mb_* functions have the advantage that they support multibyte character encodings (such as Unicode and UTF-8, the standard on the web these days), while the "standard" string functions were written for an era when ASCII was the norm. This means they can sometimes mangle text by failing to recognise the correct encoding.

In addition to converting between upper and lower case, the mb_strtoupper() function also supports case mapping and case folding. Case mapping is when characters are swapped between upper and lower case, for example STREET STRASSE. This can be useful when comparing two strings with very similar content but very different cases, for example STREET STARTS WITH.

Another useful function is mb_strcpl(), which returns the list of all the characters in a given string. This can be particularly helpful if you need to split up a string into multiple pieces or use the string in a regex pattern.