How does PHP deal with emoji expressions in characters
This article mainly introduces "how PHP handles emoji expressions in characters". In daily operation, I believe many people have doubts about how PHP handles emoji expressions in characters. Xiaobian consulted all kinds of materials and sorted out simple and easy operation methods. I hope to help you answer the doubts about "how PHP handles emoji expressions in characters"! Next, please follow the small series to learn together!
utf-8 encoded emoji or certain special characters take up 4 bytes. Common Chinese characters encoded by utf-8 take up 3 bytes.
Three PHP built-in functions:
mb_strlen
mixed mb_strlen ( string $str [, string $encoding = mb_internal_encoding() ] ) //Returns the number of characters in string str with encoding. Multibyte characters are counted as 1.// Returns FALSE if the given encoding is invalid
mb_substr
string mb_substr ( string $str , int $start [, int $length = NULL [, string $encoding = mb_internal_encoding() ]]) //Performs a multibyte safe substr() operation based on the number of characters. Position is counted from the start of str. The position of the first character is 0. The second character is at 1.// The mb_substr() function returns the part specified in str based on the start and length arguments.
strlen
int strlen ( string $string )//Returns the length of the given string string.
Determine whether the string contains emoji
The function is as follows:
function haveEmojiChar($str){ $mbLen = mb_strlen($str); $strArr = []; for ($i = 0; $i
< $mbLen; $i++) { $strArr[] = mb_substr($str, $i, 1, 'utf-8'); if (strlen($strArr[$i]) >= 4) { return true; } } return false;}
Remove emoji from string
The function is as follows:
function removeEmojiChar($str){ $mbLen = mb_strlen($str); $strArr = []; for ($i = 0; $i
< $mbLen; $i++) { $mbSubstr = mb_substr($str, $i, 1, 'utf-8'); if (strlen($mbSubstr) >= 4) { continue; } $strArr[] = $mbSubstr; } return implode('', $strArr);}
String storage with emoji in MySQL
MySQL uses the utf8mb4 character set.
PHP base64 encodes strings and decodes them when pulled from the database.
Remove emoji directly from strings (this method is simple and crude)
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