tailieunhanh - HandBooks Professional Java-C-Scrip-SQL part 221

Tham khảo tài liệu 'handbooks professional java-c-scrip-sql part 221', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | JavaScript JavaScript introduced Perl-like regular expression support with Version . This reference covers Version as defined by the ECMA standard. Supporting implementations include Microsoft Internet Explorer and Netscape Navigator 6 . JavaScript uses a Traditional NFA match engine. For an explanation of the rules behind an NFA engine see Section . Supported Metacharacters JavaScript supports the metacharacters and metasequences listed in Table 1-41 through Table 1-45. For expanded definitions of each metacharacter see Section . Table 1-41. Character representations Sequence Meaning 0 Null character x00. b Backspace x08 supported only in character class. n Newline x0A. r Carriage return x0D. f Form feed x0C. t Horizontal tab x09. t Vertical tab x0B. xhh Character specified by a two-digit hexadecimal code. uhhhh Character specified by a four-digit hexadecimal code. cchar Named control character. Table 1-42. Character classes and class-like constructs Class Meaning . A single character listed or contained within a listed range. r. A single character not listed and not contained within a listed range. . Any character except a line terminator r x0A x0D u2028 u2029 . w Word character a - zA- Z0-9_ . W Non-word character Aa- zA- Z0-9_ . d Digit character 0-9 . D Non-digit character A0-9 . s Whitespace character. S Non-whitespace character. Table 1-43. Anchors and other zero-width tests Sequence Meaning A Start of string or after any newline if in multiline match mode m. End of search string or before a string-ending newline or before any newline if in multiline match mode m. b Word boundary. B Not-word-boundary. . . . Positive lookahead. . Negative lookahead. Table 1-44. Mode modifiers Modifier Meaning m A and match next to embedded line terminators. i Case-insensitive match. Table 1-45. Grouping capturing conditional and control Sequence Meaning . Group subpattern and capture submatch into 1 2 . and 1 2 . n In a regular expression .