Odd behavior for replacing newlines in PHP

问题

I've encountered some strange behavior with PHP. I have a string of text from a <textarea/> input and it seems that:

$text = str_replace(array("\r\n", "\r", "\n"), null, $text);

successfully removes the newlines, whereas

$text = str_replace("\n", " ", $text)
$text = str_replace("\r\n", " ", $text)
$text = str_replace("\r", " ", $text)

EDIT: the three str_replace calls above are for \n, \r\n, and \r

does NOT successfully remove newlines. I even tried adding:

$text = str_replace(PHP_EOL, " ", $text);

but it doesn't fix the problem. I know I'm replacing the newlines with a space instead of null, but I would expect this to also work. After doing the 3-4 str_replace() calls, if I:

echo nl2br($text);

it does in fact find some remaining newline characters.

Any ideas?

回答1:

Text coming from an textarea ALWAYS has \r\n linebreaks.

So you should just do $text = str_replace("\r\n", '', $text);

See the spec for more info.

回答2:

You should use:

$text = str_replace("\r\n", " ", $text)
$text = str_replace("\r", " ", $text)
$text = str_replace("\n", " ", $text)

or

$text = str_replace("\r\n", null, $text)
$text = str_replace("\r", null, $text)
$text = str_replace("\n", null, $text)

来源：https://stackoverflow.com/questions/10128508/odd-behavior-for-replacing-newlines-in-php