php去除重复字的实现代码

$text = '数组aabbccdd'; 
$text_filter = ''; 
$filter = array(); 
$len = mb_strlen($text, 'utf-8'); 
for ($i = 0; $i<$len; $i++) { 
$char = mb_substr($text, $i, 1, 'utf-8'); 
if (!isset($filter[$char])) { 
$text_filter .= $char; 
$filter[$char] = $char; 
} 
} 
echo $text_filter;

$string= '数组aabbccdd'; 
function str_split_utf8($str) { 
$split=1; 
$array = array(); 
for ( $i=0; $i < strlen( $str ); ){ 
$value = ord($str[$i]); 
if($value > 127){ 
if($value >= 192 && $value <= 223) 
$split=2; 
elseif($value >= 224 && $value <= 239) 
$split=3; 
elseif($value >= 240 && $value <= 247) 
$split=4; 
}else{ 
$split=1; 
} 
$key = NULL; 
for ( $j = 0; $j < $split; $j++, $i++ ) { 
$key .= $str[$i]; 
} 
array_push( $array, $key ); 
} 
return $array; 
} 
print_r(array_unique(str_split_utf8($string)));