String function: preg-replace

Question

I have not achieved result as expected. Here is what my string and code look like in PHP.

$string in text box

"This is 《Carriage Return》
a 《Carriage Return》
test"

Then using code in PHP:

$cleanstring=preg_replace('/\s+/', ' ', $string); //(' ' has a space in between)

Result came out as:

$cleanstring="This is\r\na\r\ntest"

But I expected it to be as "This is a test"

Answer 1

找到了有效的代码：

$cleanstring=trim(preg_replace('/\s{1,}/', ' ', $string));