RegExp.prototype.dotAll

The dotAll accessor property of RegExp instances returns whether or not the s flag is used with this regular expression.

RegExp.prototype.dotAll has the value true if the s flag was used; otherwise, false. The s flag indicates that the dot special character (.) should additionally match the following line terminator (“newline”) characters in a string, which it would not match otherwise:

U+000A LINE FEED (LF) (n) U+000D CARRIAGE RETURN (CR) (r) U+2028 LINE SEPARATOR U+2029 PARAGRAPH SEPARATOR

This effectively means the dot will match any UTF-16 code unit. However, it will not match characters that are outside of the Unicode Basic Multilingual Plane (BMP), also known as astral characters, which are represented as surrogate pairs and necessitate matching with two . patterns instead of one.