A regular expression which in short is known as regex or regexp is also at times known as a rational expression. It is a set of characters arranged in a sequence that is used to form a search pattern and is used for “find and replace” like tasks. It is mainly used for pattern matching operations for strings and is used in theoretical computer science. This concept was introduced in the 1950s by an American mathematician called Stephen Kleene and is very extensively used in the
UNIX operating system for its text processing utility called “ed” and the grep filter. Grep stands for global regular expression and a filter. Many commonly used
commands on Linux operating system use regular expressions for find and replace type of tasks.
Regex are also heavily used for string manipulation operations like
split and
trim in Java programming language.
Below are some tools and websites that can help you write and test regular expressions much faster.
