你在\n前加入123如print("<B>counter is $counter</B><BR>123\n");就知道\n它没有换行的功能了,它就像是普通字符一样
\n是对html代码起换行作用,对html显示内容无换行作用查看源代码时 <B>counter is counter</B><BR>\n<B>counter is counter</B><BR> 显示为 <B>counter is counter</B><BR> <B>counter is counter</B><BR><B>counter is counter</B><BR><B>counter is counter</B><BR> 显示为 <B>counter is counter</B><BR><B>counter is counter</B><BR> 另外 print("<B>counter is $counter</B><BR>\n"); 建议写作 echo '<B>counter is ',$counter,'</B><BR>',PHP_EOL;至于为什么这样写,自己去学习一下,有助你记忆
“新人”必学:
http://www.w3school.com.cn/xhtml/index.asp
http://cn.php.net/manual/zh/
echo "<div>1<br />1</div>";
echo "<div>1\n1</div>";
?>
右键->查看源文件(源代码)
<B>counter is counter</B><BR>\n<B>counter is counter</B><BR>
显示为
<B>counter is counter</B><BR>
<B>counter is counter</B><BR><B>counter is counter</B><BR><B>counter is counter</B><BR>
显示为
<B>counter is counter</B><BR><B>counter is counter</B><BR>
另外
print("<B>counter is $counter</B><BR>\n");
建议写作
echo '<B>counter is ',$counter,'</B><BR>',PHP_EOL;至于为什么这样写,自己去学习一下,有助你记忆