UTF-8 Encoding in PHP and MySQL

UTF-8 is an international character set that supports essentially all written languages in the modern world.

UTF-8 is an international character set that supports essentially all written languages in the modern world. It is a superset of ASCII, with support for characters from the entire Unicode character set. It can represent over one million different characters, including:

• About 136,000 ideographs used in Chinese, Japanese and Korean languages

• Over 60,000 symbols

• A wide assortment of emoji

In total, UTF-8 makes use of 1 to 4 bytes per character. If you're using ASCII characters only (such as the English alphabet), a single byte is sufficient to represent all possible characters. Other languages will often require 2 or more bytes; for example most emoji consist of four bytes each.

 

UTF-8 does not include non-language characters like emojis, however.

In addition to most written languages, UTF-8 also supports other fun characters such as é and ñ. However, UTF-8 does not include non-language characters like emojis, however. If you're storing content that includes emojis (like a social media app), make sure you're using a character encoding that supports emoji symbols.

UTF-8 is backwards compatible with ASCII, meaning any ASCII character is still a valid UTF-8 character.

• An example of some UTF-8 strings:*

"This is a string"

“I ♥ the UTF-8 encoding!”

“哈囉ㄚˋ！世界！”

These three strings are all valid UTF-8 encoded. The first one is a standard ASCII string, which means that it only uses characters between 0 and 127. The second uses some non-ASCII characters (a heart and a quote character), and the third uses Chinese characters.

The PHP source code should be saved as UTF-8 without BOM.

Utf-8 files should be saved as UTF-8 without BOM. The byte order mark (BOM), is a special marker added at the beginning of a Unicode text file to indicate that it is encoded in UTF-8, UTF-16BE or UTF-16LE.

The byte order mark (BOM) can be used to differentiate between big and little endian encodings and between UTF-16 and UTF32 encodings but since PHP supports only one string type most people use it to check whether the PHP source code is encoded in utf8 or not. If you are using Windows Notepad to write your code then you should save all your PHP files as "UTF-8 without BOM", otherwise you will see weird symbols in your PHP source code.

The file name of the PHP source code should not contain any accents or non-English symbols (this can cause problems for some web servers).

So when naming your PHP file, you should keep it simple. The file name of the PHP source code should not contain any accents or non-English symbols (this can cause problems for some web servers). The file name should be in English only and no spaces should be used. It is also a good idea to make sure that the name is all lower case.

All MySQL tables in the database should use the utf8mb4_unicode_ci collation.

If you have a table that was created when the default character set was latin1, you will need to convert it.

You can use ALTER TABLE command

ALTER TABLE `tbl_name` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

If you don't do this step, your queries may appear to work and save correctly, but MySQL will strip out any four-byte characters behind your back. This may produce unexpected results with comparisons and indexes because the stripped version is what is actually stored on disk and used for comparisons.

It is important to know how to set up your PHP and MySQL environment to support UTF-8 encoding

The first thing you should know is that UTF-8 is now the preferred encoding standard of the web. In fact, the W3C mandates it and thus anyone who wants to have their website validated will need to use UTF-8.

If you plan on working with languages other than English, you’ll also need to use UTF-8 as your database character set so that it can properly store and display those languages.

While using UTF-8 for your data isn’t necessarily difficult if you do it correctly, there are many common pitfalls that can be a real headache if not avoided.