php preg_replace 删除最后一个换行符？

Question

我的数据库中有以下字符串，我想删除字符串末尾的“\r\n”，我尝试了很多次，但都失败了

例如，见下文

<?php

$text = 'Am a 44 year old divorced lady with two adult sons. Having been single for 15years and dedicating my life to my two boys, am ready now to find love and companionship with a loving caring honest man with humane values\r\n\r\nThough 44 I look much younger. Look forward to meeting a like minded honest man and share the rest of our  journey of life together with mutual understanding and complement each other.       \r\n\r\nWill be happy to forward a photograph after initial dialogue\r\n';

echo $essay = preg_replace("/(\r\n)$/", ' ', $text);
echo preg_replace("/\=\r\n$/", " ", $text);

我正在用

测试这个

http://phptester.net/

但无法获得如下所示的预期输出

$text = 'Am a 44 year old divorced lady with two adult sons. Having been single for 15years and dedicating my life to my two boys, am ready now to find love and companionship with a loving caring honest man with humane values\r\n\r\nThough 44 I look much younger. Look forward to meeting a like minded honest man and share the rest of our  journey of life together with mutual understanding and complement each other.       \r\n\r\nWill be happy to forward a photograph after initial dialogue';

Answer 1

您要删除的 \r\n 不是 CR+LF 符号，而是一个 4 个字符的字符串，因为在单引号字符串文字中，\ 是文字反斜杠。因此，您的字符串以 \、r、\、n 结尾。要将文字 \ 与正则表达式匹配，您需要使用 4 个反斜杠，而不是 2 个。

参见PHP demo：

$text = 'Am a 44 year old divorced lady with two adult sons. Having been single for 15years and dedicating my life to my two boys, am ready now to find love and companionship with a loving caring honest man with humane values\r\n\r\nThough 44 I look much younger. Look forward to meeting a like minded honest man and share the rest of our  journey of life together with mutual understanding and complement each other.       \r\n\r\nWill be happy to forward a photograph after initial dialogue\r\n';
echo $essay = preg_replace("/\\r\\n$/", '', $text);

请注意，您可以只检查字符串是否以 \r\n 结尾，然后再检查 substr。

Answer 2

所以首先你需要把单引号'改成双引号字符串"

$text = "Am a 44 year old divorced lady with two adult sons. Having been single for 15years and dedicating my life to my two boys, am ready now to find love and companionship with a loving caring honest man with humane values\r\n\r\nThough 44 I look much younger. Look forward to meeting a like minded honest man and share the rest of our  journey of life together with mutual understanding and complement each other.       \r\n\r\nWill be happy to forward a photograph after initial dialogue\r\n";

然后使用

echo $essay  = preg_replace('/\r+\n/', '', $text);

php preg_replace 删除最后一个换行符？

php preg_replace remove the last new line character?

php

preg-replace