The mb_convert_variables() is an inbuilt function in PHP that transforms the character code into variables.

Syntax:

mb_convert_variables( $to_encoding, $from_encoding, $var, ...$vars ): string|false

Parameters: This function accepts four parameters that are described below:

• $to_encoding: The characters encoding converted into the variable.
• $from_encoding: This parameter is specified with the string separated with a comma or as an array. The detect_order will be used if omitted.
• $vars: The variable or array of variables to be converted. This parameter is passed by reference. The String, Array, and Object are taken by this variable.
• ...$vars:  This is an optional parameter. Additional variables are to be converted, and separated by commas.

Return values: If the conversion is successful, it will return "true" otherwise it will return "false". If $vars is an array, the function returns an array of the converted variables.

Example 1: The following code demonstrates the mb_convert_variables() function.

<?php
$string = "Hello, world!";
mb_convert_variables('UTF-8', 'ASCII', $string);
echo $string;    
?>

<?php

$string = "Hello, world!";

mb_convert_variables('UTF-8', 'ASCII', $string);

echo $string;    

?>

Output:

Hello, world!

Example 2: The following code demonstrates the mb_convert_variables() function.

<?php
$array = array(
  "name" => "GeeksforGeeks",
  "email" => "geeks@example.com"
 );
mb_convert_variables('UTF-8', 'ISO-8859-1', $array);
print_r($array);   
?>

<?php

$array = array(

  "name" => "GeeksforGeeks",

  "email" => "geeks@example.com"

 );

mb_convert_variables('UTF-8', 'ISO-8859-1', $array);

print_r($array);   

?>

Output:

Array
(
    [name] => GeeksforGeeks
    [email] => geeks@example.com
)

Reference: https://www.php.net/manual/en/function.mb-convert-variables.php