New Lock class . The Lock class allows safe sharing of information with multiple incoming requests. Changes to the Number object . Number now produces NaN rather than an error if x is a string that does not contain a well-formed numeric literal. New RegExp object for regular expressions .
Regular expressions are patterns used to match character combinations in strings.
You create a regular expression as an object that has methods used to execute a match against a string. You can also pass the regular expression as an argument to the String methods match , replace , search , and split . The RegExp object has properties most of which are set when a match is successful, such as lastMatch which specifies the last successful match. The Array object has new properties that provide information about a successful match such as input which specifies the original input string against which the match was executed. See RegExp for information.