最近在跟着 php和mysql web开发 这本书学习,在运行以下php语句的循环时出现502错误。
想循环输出一个表格:
<!DOCTYPE html>
<html>
<head>
<title>Bob's Auto Parts - Freight Costs</title>
</head>
<body>
<table style="border: 0px; padding: 3px">
<tr>
<td style="background: #cccccc; text-align: center;">Distance</td>
<td style="background: #cccccc; text-align: center;">Cost</td>
</tr>
<?php
$distance = 50;
while ($distance <= 250) {
echo "<tr>
<td style=\"text-align: right;\">".$distance."</td>
<td style=\"text-align: right;\">".($distance / 10)."</td>
</tr>\n";
$distance += 50;
}
?>
</table>
</body>
</html>
但是光这种简单的循环还是能成功显示(输出1~5):
<?php
$num = 1;
while ($num <= 5){
`echo $num."<br />";
$num ++;
}
?>
望大佬解决,谢谢