Find and Replace with Regular Expressions Search-and-replace is a common job for regular expressions. The output is the string subject to all of the regular expression matches is replaced with the replacement text. Although the text does not substitute regular expressions at all, you can use certain special syntax to build a dynamic text replacement. All sense of letting you re-enter the text that matches the regular expression capture groups to replacement. Many think the idea of replacement text differently by various software developers have created a regular expression regular expression in a variety of flavors, each with a different syntax and set of features. In fact, there are even more sense of the replacement text of a sense of regular expressions. The result is that there is a sense many of the replacement text for regular expression libraries that do not have a built-in search-and-replace feature. Fortunately, all flavors of regular expression in this book has a sense of the appropriate replacement text, except for PCRE. on page 2 for more details about the sense of regular expressions that match with the replacement text flavors: Perl Perl has a built-in support for regular expression substitution via s / regex / replace / operator. The replacement text flavor according to taste Perl Perl regular expressions. The latest version adds support for backreferences mentioned in the replacement text, as it adds named capture for regular expression syntax book. PHP is In, replacement PHP flavor text refers to the function preg_replace in PHP. This function uses regular expressions PCRE flavor and taste PHP replacement text. Depending on where your programming language designers get their inspiration, the replacement text syntax may be similar to PHP or any other flavor substitute text in this book. This function uses a different flavor of regular expressions (POSIX ERE), and a different flavor as well the replacement text. NET replacement. Flavor text in accordance with the sense of regular expressions. NET. Regular Expressions new features in 2.0. NET does not affect the replacement text syntax. JavaScript In this book, we use the term JavaScript to show good taste and flavor text replacement regular expression is defined in the 3rd Edition of ECMA-262 standard. The replacement text flavor according to taste Python Python regular expressions. A compilation of Ruby 1.8 by default uses the regular expression flavor directly by the source code for Ruby, while compiling Ruby 1.9 library Oniguruma default using regular expressions. In this book, we show the original flavor as Ruby Ruby 1.8, and a sense of Oniguruma as Ruby 1.9. Replacement text syntax for Ruby 1.8 and 1.9 are the same, except that Ruby 1.9 adds support for backreferences mentioned in the text replacement.