数组值拼接成字符串

<?php
class Convert 
{
	public static  function arrayConvertString( $array ,$join )
	{
		$result = "" ;
		
		foreach ( $array  as $k => $v )
		{
			if( is_array( $v ) )
			{
				$result .= $join. self::arrayConvertString( $v , $join ) ;
			}
			else
			{
				$result .= $join . $v ;
			}
			$result = preg_replace( "~^" . $join . "~" , "", $result ) ;
		}
		
		return $result ;
	}
}
// test
$array = array( array(1,2,3,4,5),array("x1","x2","x3","x4","x5") ) ;
$str = Convert::arrayConvertString( $array , ",") ;
echo $str ;
// echo:1,2,3,4,5,x1,x2,x3,x4,x5
?>