<? PHP /* POSIX extended regular expression Functions */ /* --------------------------------------------------- */ $ Ereg = '^ [$] [[: Alpha:] _] [[: alnum:] *' ; Ereg ( $ Ereg , '$ _ Name ', $ Register ); // Match and store arrays // eregi () case-insensitive Var_dump ( $ Register ); // Display Array Structure /* --------------------------------------------------- */ $ Ereg = 'TT' ; $ Str = 'Hello, TM' ; $ Rep_str = Eregi_replace ( $ Ereg , 'TT ',$ Str ); // If the matching is successful, use TM to replace ereg_replace () in case sensitivity. Echo $ Rep_str ; /* --------------------------------------------------- */ $ Ereg = 'Is' ; $ Str = 'This is a register book .' ; $ Arr_str =Spliti ( $ Ereg , $ Str ); // Split the string. Split () matching by regular expression is case sensitive Var_dump ( $ Arr_str ); /* PCRE is compatible with regular expression functions-PCRE is slightly better than POSIX in terms of efficiency or syntax */ /* --------------------------------------------------- */ $ Preg = '/\ D {3, 4 }-? \ D {7, 8 }/' ; $ Arr = Array ('20140901', '2014-043212345678 ', '20140901 '); // Contains element array $ Preg_arr = Preg_grep ( $ Preg , $ Arr ); Var_dump ( $ Preg_arr ); /* --------------------------------------------------- */ $ Str = 'This is an example! ' ; $ Preg = '/\ B \ W {2} \ B /' ; $ Num1 = Preg_match ( $ Preg , $ Str , $ Str1 ); // Match and return the number of successful results. After the successful match is put into the array, it stops. Echo $ Num1 . "<Br/>" ; Var_dump ( $ Str1 ); Echo "<Br/>" ; // Returns the number of successful matches. After successful matches are put into the array, the system does not stop until all matching characters are completed. $ Num2 = Preg_match_all ( $ Preg ,$ Str , $ Str2 ); Echo $ Num2 . "<Br/>" ; Var_dump ( $ Str2 ); /* --------------------------------------------------- */ $ Str = '! , $, ^, *, +,., [,], \,/, B, <,>' ; $ Str2 = 'B' ; // Automatically escape special regular expressions. If a parameter exists, the characters containing the parameter are also escaped. $ Match_one = Preg_quote ( $ Str , $ Str2 ); Echo $ Match_one ; /* --------------------------------------------------- */ $ String = '[B] Bold [/B]' ; // Reverse references are used for matching and replacement. $ B _rst = Preg_replace ('/\ [B \] (. *) \ [\/B \]/I', '<B> $1 </B> ', $ String ); Echo $ B _rst ; /* --------------------------------------------------- */ Function C_back ( $ Str ){ // Reverse reference $ Str = "<Font color = $ Str [1]> $ Str [2] </font>" ; Return $ Str ;} $ String = '[Color = Blue] font blue [/color]'; // The character to be replaced in the preg_replace_callback function. It is only the same as the preg_replace function. Echo Preg_replace_callback ('/\ [Color = (. *) \] (. *) \ [\/color \]/U', "c_back ", $ String ); /* --------------------------------------------------- */ // No in this function book. I will give you my own examples! $ Preg = "/\ S + /";// Here you can also change to "/\ s {1 ,}/"; $ Str = "I'm Chinese! I can eat" ; $ Arr = Preg_split ( $ Preg , $ Str ); // Search and split. -- There is a written mistake here. The friends I have read can't help but have corrected it now. Var_dump ( $ Arr ); ?>