What are regular expressions?
Strings are a vital topic when it comes down to software development. We are always dealing with strings; be it in message outputs, alerts, form inputs, pattern matching, shell outputs and much more.
We couldn't even imagine a single program without even the least usage of strings. The theory is simple - strings are king!
Anyways, the point here is not to emphasize what strings are but instead what is their level of usage in software. And what's even more important is that majority of the times when working with strings, we don't just want to print them right away to the screen, but instead process them. We might need to change their casing, extract a slice out, replace occurences of a some word or pattern, find a given sequence of words or a pattern and so on.
Specifically, when it comes down to searching for stuff within a string we have, at our dispense, a highly powerful and a fairly complex technology to do this known as regular expressions.
Regular expressions in programming are expressions used to match certain patterns within strings. When we talk about regular expressions, or simply regexp, we are in effect talking about strings.
Regular expressions are compact, powerful and sometimes pretty ugly, yet a common technology of searching substrings inside strings in nearly all languages. Programming languages such as the low-level C, the high level Python, Java, PHP, Perl, all support regular expressions out of the box.
There will be quizes, exercises, questions answers, in short - a whole lot of fun and learning.
So are you ready to begin!!!