为什么这个命令输出一个预期大小的空数组，而不是一个填充了元素的数组 - Why does this command output an empty array of the expected size instead of one with the elements filled in?

Why does this command output an empty array of the expected size instead of one with the elements filled in?

我想让一个用户在文本区域中键入几行，然后让php将它们分配给一个数组，但是我的代码似乎将空值分配给数组

HTML:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtm$
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h1>Juniper to IOS Translator</h1>
<form method="post" action="query.php">
 <textarea name="txtarea" style="width: 80%; height: 25em;">
 </textarea>
 <input type="submit" />
</form>

PHP：

<?php
$text = $_POST["txtarea"];
echo nl2br($text);
echo "<br />" , "<br />";
$data = preg_split("/((?<='n).*?(?='n))/", $text , -1, PREG_SPLIT_NO_EMPTY);
print_r(array_values($data));
?>
</body>
</html>

带输入：

Line with stuff 
Line with stuff more
Line with stuff more more
Line with stuff more more more
Line with stuff more more more more

我得到输出：

Line with stuff 
Line with stuff more
Line with stuff more more
Line with stuff more more more
Line with stuff more more more more

Array ( [0] => [1] => [2] => [3] => [4] => [5] => )

我传错阵了吗？我的正则表达式错了吗？

使用

$data = preg_split("/'R/", $text , -1, PREG_SPLIT_NO_EMPTY);

其中''R表示行的末尾。

preg_split将分隔符作为第一个参数。但您尝试使用文本（而不是行尾）作为分隔符，并成功地只获得了行尾作为数组。

如果我很清楚你打算做什么，也许这个正则表达式是正确的：

$data = preg_split("/'n/", $text , -1, PREG_SPLIT_NO_EMPTY);