Blog Archives

8 Regular Expressions (aka Regex) by examples for Java developers

Q1 How will you go about implementing the following validation rules for a user name? — user name must be between 2 and 17 characters long. — valid characters are A to Z, a to z, 0 to 9, . (full-stop), _ (underscore) and – (hyphen) — user name must…

Read more ...


Power of regex for productivity with Notepad++ or Sublime Text

This post is based on industrial strength examples of applying regular expression to increase your productivity as a software engineer. Many text editors like Notepad++, Sublime Text, Atom, etc support regular expressions in their find and replace functionality. If you are new to regular expression, practice at https://regexr.com/ or https://regex101.com/…

Read more ...


Regular Expressions interview Q&As for Java developers

Q1 What’s the difference between a wildcard and a regular expression? A1 A wildcard is a generic term referring to something that can be substituted for all possibilities. In computer terms, usually a simple “wildcard” is just a * that can match one or more characters, and possibly a ?…

Read more ...


Regular Expressions Practice – Java Matcher class csv example

Let’s look at how to validate a CSV (i.e. Comma Separated Value) string using regular expression in Java using the Pattern & Matcher classes. Refer to the Java Pattern class API for what each syntax mean. Regular expressions may look complex, but if you understand the patterns and break them down into simpler steps, they will become easier to comprehend.

Comma separated digits

The below is a simple example of how to validate comma separated digits.… Read more ...



Regular Expressions Practice – Java Matcher class tokenize example

If you are new to regular expressions then start with 8 Regular Expressions (aka Regex) by examples for Java developers.

This is a real life scenario as to how regular expressions can come in handy to solve day to day problems. Regular expressions are very powerful and can be used by developers & data engineers to solve problems & save time.… Read more ...



Java Developer & Architect Q&As

Big Data Engineer & Architect Q&As

16+ Key Areas & 13+ Techs to fast-track