I am new to programming, and at an interview I got a question on regular expressions; needless to say I couldn't answer. So I was wondering whether I should learn regular expression? Is it a must for every programmer of all fields? Or it is a must for programming for some particular fields?

Related questions:


Why are regular expressions so morbidly attractive?
When you should NOT use Regular Expressions?


Regular expressions are such an incredibly convenient tool, available across so many languages that most developers will learn them sooner or later.

For an interviewer, they are a nice way to probe experience during an interview. If you are interviewing someone claiming years of experience who doesn't understand them, you need to dig further.
