Why are people using regexp for email and other complex validation?

Question

There are a number of email regexp questions popping up here, and I\'m honestly baffled why people are using these insanely obtuse matching expressions rather than a very si

Answer 1

People write regular expressions because most developers like so solve a simple problem in the most "cool" en "efficient" way (which means that it should be as unreadable as possible).

In Java, there are libraries to check if a String represents an email address without you having to know anything about regular expressions. These libraries should be available for other languages aswel.

Like Jamie Zawinski said in 1997: "Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems."