What is regex used for?
Regex is short for regular expression, a regex is a string of text which you can use to create patterns that help match, locate, and manage text.
How does regex work?
Almost all modern regex flavours are based on regex-directed engines. If a match is found, the engine advances through the regex and the subject string. If a token fails to match, the engine backtracks to a previous position in the regex and the subject string where it can try a different path through the regex.
Are regular expressions important?
Regular expressions are a very terse way to express how to match patterns in text. The requirement to parse and extract data from text or to validate that some text conforms to a specific pattern comes up very often in programming. It is important to learn about regex and at least know what to google when you encounter one or need to use it.