perl string substring

9 Regular Expressions in PerlThree forms of regular expressionsCommon patterns in regular expressions8 Principles of Regular expressionsRegular expressions are a major feature of the Perl language and a bit of a problem in Perl, but if you can

Thanks to aka and the author. Regular Expressions in PerlThree forms of regular expressions Common patterns in regular expressions The 8 major principles of regular expressions Regular expressions are a major feature of the Perl language and a

Regular expressions are a major feature of the Perl language and a bit of a pain in the Perl program, but if you have a good grasp of him, you can easily use regular expressions to complete the task of string processing, of course, in the CGI

As we all know, Perl is very powerful in processing strings, and Perl (Practical Extraction and Reporting Language) is also very powerful in processing formats. Here we start to learn some Perl formats and string processing. Familiar with the three

Matches: m/;/ (can also be shortened to/;/, omit m)Replacement: s/;/;/Conversion: tr/;/;/These three forms are generally used in conjunction with =~ or!~ (where "=~" means matching, read as does in the entire statement, "!~" for mismatches, read as

Regular Expression. The so-called regular expression is a set of character sets starting from the slash ring. They can be used to match the specified modulo in the text.And perform the replacement operation. Perl has always been famous for its

[File handle] $| If Non-zero, force clear buffer after write or print operation on the currently selected file$% the current page number of the currently selected file handle$= the current page length of the currently selected file handle$-the

first, open, close the file The return value of open is used to determine whether the operation that opened the file succeeds, returns a value other than 0 when it succeeds, and returns zero when it fails, so it can be judged as follows:if (Open

Process processing functions 1. Process Start functionFunction name EvalCall Syntax eval (string)The commentary considers a string as a Perl statement execution.When executed correctly, the system variable $@ is an empty string, and if there is an

24 hours of Perl programming course questionsI. multiple choice questions1. Which of the following strings is incorrectly defined ()(1) 'Thank you'(2 )""(3) "A" friend "of yours"(4) "A/" friend/"of yours"2. Which of the following statements is