Convert UniCode Escape Character to UTF-8

unicode2html.php

<?php

// Works Perfict
function uni2html($string){
	//preg_replace(): Compilation failed: PCRE does not support \L, \l, \N{name}, \U, or \u at offset 1.
	//so can't use $string = preg_replace('/\\u([0-9A-Za-z]+)/', '&#x$1;', $string); directly.
	$string = explode('\\', $string);
	$string = implode('%', $string);
	$string = preg_replace('/%u([0-9A-Za-z]+)/', '&#x$1;', $string);
	return html_entity_decode($string, ENT_COMPAT, 'UTF-8');
}
// this also works perfict
function unicode2html($string){
	$string = explode('\\', $string);
	$string = implode('%', $string);
	$string = preg_replace('/%u([0-9A-Za-z]+)/', '&#x$1;', $string);
	return mb_convert_encoding($string, 'UTF-8', 'HTML-ENTITIES');
}
// Works Perfict
function unicode_escape_sequences($str){
  	//$working = json_encode($str);
	$working = preg_replace('/\\\u([0-9a-z]{4})/', '&#x$1;', $str);
	return $working;// json_decode($working);
}

// Works Perfict
function replace_unicode_escape_sequence($match) {
    return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UCS-2BE');
}
echo $str = preg_replace_callback('/\\\\u([0-9a-f]{4})/i', 'replace_unicode_escape_sequence', $string);

// Works Perfict
echo preg_replace_callback('/(?:\\\\u[0-9a-fA-Z]{4})+/', function ($v){
	$v = strtr($v[0], array('\\u' => ''));
	return mb_convert_encoding(pack('H*', $v), 'UTF-8', 'UTF-16BE');
	}, $string);


// One of the easiest way & works really well.
// json_decode function automatically convert unicode character into readable html
print_r(json_decode($string));

// This Also Works
$unicodeChar = '\u1000';
echo json_decode('"'.$unicodeChar.'"');
?>