JavaScript Regular expression-definition

JavaScript defines a regular expression in two ways:

1. Create a RegExp object from the RegExp () constructor to define the regular expression .

2. direct definition of regular expression by literal grammar .

To define a regular expression by creating an RegExp object with the RegExp () constructor

var New Regext ("a\d");

Direct definition of regular expressions by literal syntax

var reg_pattern =/a\d/; // pattern matching string is: After the letter a followed by an arbitrary number // the 2nd slash can then be followed by a prefix option (tag) to illustrate the rules for pattern matching.  var reg_pattern =/a\d/g; // g represents all matching strings in the search string.  varnew regext ("a\d", "G"); var reg_pattern = "a\\d"new regext (Reg_pattern, "G");

JavaScript Regular expression-definition