Regular expression-why does the PHP match the Chinese characters in the regular mode modifier when it is not added?

The situation is as follows:

• PHP 5.5.11
• Mac OSX 10.9.2, Win7, CentOS 6.3

The code is as follows:

echo preg_replace('/[\s-]+/', '-', '阿树')."\n";

The test results are as follows:

• Mac garbled
• Windows, Linux are normal

Add mode modifier after normal, as follows:

echo preg_replace('/[\s-]+/u', '-', '阿树')."\n";

Look for information, so to speak:

U (PCRE_UTF8)

This modifier enables additional features in a PCRE that are incompatible with Perl. The pattern string is treated as UTF-8. This modifier is available under Unix from PHP 4.1.0 and is available under Win32 from PHP 4.2.3. starting from PHP 4.3.5 Check the UTF-8 legitimacy of the mode.

Excuse me:

1. Do you mean to use matching characters as UTF8, and do you have any other effects?
2. My code is UTF8, but why is only Mac (Unix) garbled?

Reply content:

The situation is as follows:

• PHP 5.5.11
• Mac OSX 10.9.2, Win7, CentOS 6.3

The code is as follows:

echo preg_replace('/[\s-]+/', '-', '阿树')."\n";

The test results are as follows:

• Mac garbled
• Windows, Linux are normal

Add mode modifier after normal, as follows:

echo preg_replace('/[\s-]+/u', '-', '阿树')."\n";

Look for information, so to speak:

U (PCRE_UTF8)

This modifier enables additional features in a PCRE that are incompatible with Perl. The pattern string is treated as UTF-8. This modifier is available under Unix from PHP 4.1.0 and is available under Win32 from PHP 4.2.3. starting from PHP 4.3.5 Check the UTF-8 legitimacy of the mode.

Excuse me:

1. Do you mean to use matching characters as UTF8, and do you have any other effects?
2. My code is UTF8, but why is only Mac (Unix) garbled?

The UTF8 of the tree says yes e6 a0 91 . Sensitive words to see here should be understood.

The second byte a0 and \n is the same, which is replaced by-the left and right side of the two bytes into illegal ASCII, displayed as a question mark, as for platform differences, is estimated to be the so-called pcre problem bar, is interested in drilling to find out

