Many programming languages feature regular expressions—or “regex” for short—which are used to find patterns in strings of text. A regex library is a mini-language for describing patterns ...

An alternation is the simplified form of if-then-else available in the regular expression language. Let's start with a simple example. Suppose you wanted to match a1 or b2.

You want to find whether a date is after 25-09-2003. This involves using two features of regular expressions known as grouping and alternation. A grouping is simply a match found earlier in the string ...

There is still much more to the Regular Expression language, but it’s time to shift focus to some code examples. To work with Regular Expressions, the .NET Framework offers the Regex class in ...

ECMAScript supports regular expressions, which means you can push regular expression validation to the client. (The simpler-to-write System.DateTime comparison must take place at the server.) Here's ...

A long time ago, I wrote a utility for an employer that allowed testers to perform verification on data coming out of a hardware box using a regular expression language. It allowed users to ...

Regular expressions, or ‘regex’, are like an in-line programming language for text searches that allow you to include complex search strings, partial matches and wildcards, case-insensitive ...

For this work with regular expressions, we will start with a browser-based tool. Below is a list of file names. We want to write a regular expression that captures parts of each string. Copy the text ...

Manipulate Text With Regular Expressions Determine whether a given date is greater than or equal to a predefined date, and learn how to add to the list of Standard Expressions in the Regular ...