function jin($flow){
$arr1 = array('.');
$b = '';
$b = str_pad($b, 5,".");
$arr2 = array('*');
$k = '';
for($i=1;$i<=$flow;$i++){
$b = substr($b, 1);
array_push($arr1, $b);
echo $arr1[$i];
$k = str_pad($k, 2*$i-1,'*');
array_push($arr2, $k);
echo $arr2[$i]."<br />";
}
}
jin(5);
1 string.replace("."," ")
replace()