Question

我知道^和$，但我想删除字符串的最后一个空行，而不是每个。

$s = 'Foo

Bar

Baz
';

应该返回

$s = 'Foo

Bar

Baz;

如何使用正则表达式在PHP中完成？

您可以在此处试用：http://codepad.viper-7.com/p3muA9

Answer 1

<?php

$s = 'Foo

Bar

Baz
';

$s_replaced = preg_replace('//', '', $s);

$s_replaced = rtrim($s_replaced);
$out = '<textarea cols=30 rows=10>'.$s_replaced.'</textarea>';

echo $out;

?>

使用rtrim()。

Answer 2

使用：

$s_replaced = preg_replace("/".PHP_EOL."$/", '', $s);

Answer 3

试试这个：

查找：

(?s)\s+$

替换为：

none

<强>解释

<!--
(?s)\s+$

Options: case insensitive; ^ and $ match at line breaks

Match the remainder of the regex with the options: dot matches newline (s) «(?s)»
Match a single character that is a “whitespace character” (spaces, tabs, and line breaks) «\s+»
   Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Assert position at the end of a line (at the end of the string or before a line break character) «$»
-->

剥去一个字符串的最后一行空行？

3 个答案: