php factorial
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk" />
<title>php阶乘</title>
</head>
<body >
<?php
if (isset($_POST['button'])) {
$num = $_POST['num'];
if ($num =='' || ! is_numeric($num) || $num < 0)
{
echo '请输入大于等于0的数字';
}
else
{
$num+= 0;
if (true)
{
if ($num==0)
{
echo '0!是1';
}
else
{
$result=1;
for($i=1;$i<=$num;$i++)
{
$result*=$i;
}
echo "{$num}!是{$result}";
}
}
else
{
echo '您收入的不是整数';
}
}
}
?>
<form action="" method="post" name="form1">
<table width="500" border="1">
<tr>
<th colspan="2">求阶乘</th>
</tr>
<tr>
<td>请输入一个数</td>
<td><input name="num" id="num" type="text" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" name="button"
id="button" value="提交" /></td>
</tr>
</table>
</form>
</body>
</html>
