代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>3.1</title>
</head>
<body>
<table width="200" border="0">
<tr>
<td> </td>
</tr>
</table>
<?php
echo "<table width='200' border='1' bordercolor='#00000F' >";
for($a=0;$a<1;$a++) { //for循环做一个1*4的表格
echo "<tr>";
for ($b = 0; $b <4; $b++) {
echo "<td>";
$arr = explode("/", $_SERVER['HTTP_USER_AGENT']); //把字符串分割为数组“/”作为分界点分割出来多个子字符串
echo $arr[$b];
echo "</td>";
}
echo "</tr>";
}
echo "</table>"
?>
</body>
</html>
效果图：
