PHP with notes 3

  [a-z]*/# excluded characters [^]# [^a-za-z] except for characters other than the # # qualifier (? *+{n,m})/*? Match the preceding character 0 times or once colo?r can match colour color+ match the preceding character once or more Go+gle can match Google to go...ogle* match the preceding character 0 or more Go*gle can match ggle to Go...ogle {n} matches the preceding character n times {n,} matches the preceding character at least n times {n,m} matches the preceding character at least n times at most m times */#7 dot character/* can represent any character other than line break such as the match first letter is an S-tailed letter is a three-letter word of T, ^s.t$*/#8 escape character /* Consistent with C in Java */#9 backslash (\)/* Backslash defines some non-display such as \b BACKSPACE \ n newline, etc. */#10 parenthesis/* Change the scope of the qualifier */#11 Reverse Reference/* The reverse reference is the memory function of a test expression matching successive occurrences of a string or letter such as matching consecutive two it first put the word it as a group and then add "\1" to the format: (IT) \1//Where this 1 represents the number of groupings because there may be multiple groupings */#12 pattern modifiers/*i    Ignore case m multiple text form string contains multiple newline characters that affect ^$ 's match s single text form. You can match $^x to ignore whitespace character modifiers in three formats: (? i) TM (?-i), (? i:tm),/tm/i*/#php中POSIX扩展正则表达式函数 /*bool Erge/eregi (string pattern, string string[, array regs]) finds pattern in string, and if there is a third argument, the matched string is divided into the array. The first case-sensitive The second does not differentiate between *//*bool ereg_replace/eregi_replace (string pattern, string replacement, string string) that matches the pattern in string strings, If the result is replaced with replacement and returns the replacement string, the first case-sensitive second type is not *//*array split/split (string pattern, string string[, int limit]) Use the pattern to split a string that has parameter limitThe words are the number of restricted partitions */#PCER兼容正则表达式函数/*array Preg_grep (string pattern, array input) function using the input one by one matching expression pattern    Finally, all arrays of all matching successful elements are returned */$input = array (' Hellojimbo ', ' Nihaoajinbo ');    $pattern = '/j...o/';    $arr = Preg_grep ($pattern, $input);    echo sizeof ($arr); for ($i = 0; $i < sizeof ($arr); $i + +) {echo "$arr [$i]
"; }/* int Preg_match/preg_match_all (string pattern, string subject[, array matches]) matches the expression pattern in the string subject Number of matches, if matches,/*/* string Preg_quote (String str[, String delimiter]) automatically escapes all special characters in Str if there is a delimiter parameter The characters inside the number delimiter are also escaped */* preg_replace (mixed pattern, mixed replacement, mixed subject[, int limit]) in SUBJEC T matches pattern, matches to replace with replacement, limit number preg_replace_callback (mixed pattern, callback callback, mixed subject[, int l    Imit]) is functionally identical except that replacement is more flexible than the callback function *//*array Preg_split (string pattern, string subject[, int limit]) to split the string */?>

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