Which regular expression can be used to match a Dogecoin address? An expression that matches a Dogecoin Address must ensure the address starts with a D, followed by one character from the digits 5 to 9 or capital letters A to U (but excluding capital letters I and O), and finally followed by 32 more … Read more »
So you’ve heard that regex is a quick and easy way to help you evaluate user input or scrape information from a body of text. This article presents a complete overview of the topic and the syntax to get you started. So what is regex anyway? Regular expressions (or simply regex) are small pieces of … Read more »
After writing a brand new regular expression, it’s very important that you put it through some tests to see if it performs as you intended. How does one go about testing such an expression? To test a regular expression, first search for errors such as non-escaped characters or unbalanced parentheses. Then test it against various … Read more »
There are some grand tools online these days that allow you to write and test just about any regular expression out there using color coding, code explanation, substitution, etc. In this post, we make a thorough comparison of three regex tester tools: Regex101, Regexr, and RegexTester.
Thousands of regular expressions are written by programmers around the world each day to validate user input or to find common patterns in strings of text. Amidst all this noise, I thought it would be great to create a list of the most common regular expressions for easy access. So I did some personal research … Read more »
A regular expression for BBCode searches for a list of predefined tags enclosed in square brackets […], with possible attributes inside the tags. The list of tags depends on which tags have been implemented by the platform in question. These BBCode tags can then be replaced with valid HTML code if required.
A regular expression that validates base64 encoded data needs to check for the characters A to Z, a to z, 0 to 9, plus (+), and forward-slash (/) combined in a multiple of 4. If the number of characters is not an exact multiple of 4, the expression must search for the equal sign (=) as padding at the end.
A regular expression that matches all characters between two specified characters makes use of look-ahead (?=…) and look-behind (?<=...) statements to isolate the string, and then uses the dot character . to select all contents between the delimiters.
A regular expression that matches ASCII characters consists of an escaped string \x00 where 00 can be any hexadecimal ASCII character code from 00 to FF. A range of ASCII characters can be matched by enclosing two such codes in square brackets.
A regular expression that matches all vowels makes use of a character range (square brackets) that contains all the vowels (e.g. [aeiou]). To match double vowels or diphthongs, add a quantifier {2} behind the character range.
