PHP – How to return character by Unicode code point value using mb_chr()?

In PHP, the mb_chr() function is used to return a character by Unicode code point value. This function returns a string containing the character identified by the Unicode code point value, encoded in the specified encoding.

Syntax

string mb_chr(int $codepoint, string $encoding)

Parameters

mb_chr() accepts two parameters: $codepoint and $encoding.

• $codepoint − The Unicode code point value to convert. For example, 128024 for U+1F418 ELEPHANT.

• $encoding − The character encoding. If omitted or null, the internal character encoding value will be used.

Return Value

This function returns a string containing the requested character if it can be represented in the specified encoding, or false on failure.

Note: From PHP 8.0, nullable encoding is allowed.

Example

Here's how to convert different Unicode code points to characters using various encodings −

<?php
    $codepoints = [66, 64, 0x20AC, 128024];
    
    foreach ($codepoints as $codepoint) {
        echo "Code point: $codepoint<br>";
        var_dump(mb_chr($codepoint, 'UTF-8'));
        var_dump(mb_chr($codepoint, 'ISO-8859-1'));
        echo "<br>";
    }
?>

Code point: 66
string(1) "B"
string(1) "B"

Code point: 64
string(1) "@"
string(1) "@"

Code point: 8364
string(3) "?"
bool(false)

Code point: 128024
string(4) "?"
bool(false)

Key Points

• UTF-8 encoding supports a wider range of Unicode characters than ISO-8859-1

• When a character cannot be represented in the specified encoding, the function returns false

• The Euro symbol (?) and emoji characters require UTF-8 encoding

Conclusion

The mb_chr() function is essential for converting Unicode code points to characters in PHP. Always use UTF-8 encoding for maximum character support, especially when working with international text or emoji.