Using Java syntax in JavaScript regular expressions

The enhanced regex engine includes an additional flag to allow Java syntax to be used in JavaScript regular expressions.

Regular expressions with the additional flag work in all places that expect a regular expression, such as String.prototype.split and String.prototype.replace. To use Java syntax in a regular expression, use the Java inline flag j, for example /(?ims)ex(am)ple/j

Table 1. Extended regular expression flags
Flag Description
j Defines a regular expression that executes using the Java regular expression engine. It can be used to access Java-only features of regular expressions (such as look behind, negative look behind) or to use Java regular expressions without translating them into JavaScript regular expressions. For example: var regex = /ex(am)ple/j;