There’s a good reason the majority of programming languages support regular expressions: they are extremely powerful tools for manipulating text. Text processing tasks that require dozens of lines of code can often be accomplished with a single line of regular expression code. While the built-in functions in most languages are usually sufficient to perform search and replace operations on strings, more complex operations — such as validating text inputs — often require the use of regular expressions.

Regular expressions have been part of the JavaScript language since the third edition of the ECMAScript standard, which was introduced in 1999. ECMAScript 2018 (or ES2018 for short) is the ninth edition of the standard and further improves the text processing capability of JavaScript by introducing four new features:

Lookbehind assertions
Named capture groups
s (dotAll) Flag
Unicode property escapes