I used to use Regular Expression since first year of my web programming experience in perl and continually use in other languages (e.g. PHP, JavaScript and Java). It’s useful for matching text. I usually got question for its patterns. Many people said it’s too difficult to make understand on it. It just a easy pattern to check your string!!

Today, I saw a web that writing about this topic (in Thai) and I thought it’s too many useful for any people who’re coder/programmer or interesting.