PHP judges string encoding and obtains Chinese characters in the string + clears Spaces

Reference URL: www. w3.orgInternationalquestionsqa-forms-utf-8.en.php $ resultpreg_match ('% ^ (? : [X09x0Ax0Dx20-x7E] # ASCII | [xC2-xDF] [x80-xBF] # non-overlong2-byte | xE0 [xA0-xBF] [x80-xBF] # excludingoverlongs | [xE1

Reference URL: http://www.w3.org/International/questions/qa-forms-utf-8.en.php $ result = preg_match ('% ^ (? : [\ X09 \ x0A \ x0D \ x20-\ x7E] # ASCII | [\ xC2-\ xDF] [\ x80-\ xBF] # non-overlong 2-byte | \ xE0 [\ xA0-\ xBF] [\ x80-\ xBF] # excluding overlongs | [\ xE1

URL: http://www.w3.org/International/questions/qa-forms-utf-8.en.php

$ Result = preg_match ('% ^ (? :
[\ X09 \ x0A \ x0D \ x20-\ x7E] # ASCII
| [\ XC2-\ xDF] [\ x80-\ xBF] # non-overlong 2-byte
| \ XE0 [\ xA0-\ xBF] [\ x80-\ xBF] # excluding overlongs
| [\ XE1-\ xEC \ xEE \ xEF] [\ x80-\ xBF] {2} # straight 3-byte
| \ XED [\ x80-\ x9F] [\ x80-\ xBF] # excluding surrogates
| \ XF0 [\ x90-\ xBF] [\ x80-\ xBF] {2} # planes 1-3
| [\ XF1-\ xF3] [\ x80-\ xBF] {3} # planes 4-15
| \ XF4 [\ x80-\ x8F] [\ x80-\ xBF] {2} # plane 16
) * $ % Xs ', $ string );

If $ result is true, it is a UTF-8-encoded string, no is ANSI

Match the Chinese characters in the string with the above conditions

If ($ result ){
Preg_match_all ("/[\ xE1-\ xEC \ xEE \ xEF] [\ x80-\ xBF] {2}/", $ str, $ arr );
Print_r ($ arr [0]);
} Else {
Preg_match_all ("/[\ x80-\ xFF]./", $ str, $ arr );
Print_r ($ arr [0]);
}

Zookeeper -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

PHP clear spaces

During daily data processing, we often produce extra spaces. If you want to compare strings, this will lead to problems and waste additional storage space.

How do I remove spaces? Maybe you will first think of the PHP built-in function trim (). Yes, it does. However, in this case, it cannot handle the starting and ending parts of characters: Changing multiple spaces into one space, changing spaces into ordered queues, and so on...

Therefore, regular expressions are useful. Take a look at the following code:

$ Str = "This line contains \ tliberal \ r \ n use of whitespace. \ n ";

// First remove the leading and trailing Spaces
$ Str = trim ($ str );

// Remove the two or more spaces
$ Str = preg_replace ('/\ s (? = \ S)/', '', $ str );

// Replace a non-space with a space.
$ Str = preg_replace ('/[\ n \ r \ t]/', '', $ str );

The preceding example can remove all unnecessary spaces. Use TRim () to remove leading and trailing spaces, and then use preg_replace () to remove repeated spaces.
(? =) Indicates that only the following spaces are matched with the leading spaces.