multiline property on the
RegExp object, that changes the multiline option of new regular Expressions, is considered deprecated and will be removed in the near future. Starting with Firefox 46, the Web Console shows a deprecation warning for this property. Use the
m flag for the
RegExp literal and constructor instead. Note that the standard
multiline property on
RegExp instances won’t be removed.
Update: The support for the property has been removed with Firefox 48.