String.match(regular expression)

This executes a search for a match within a string, based on a regular expression.

var myString = "today is 12-12-2000";

var matches = myString.match(/\d{4}/);

//returns array ["2000"]

RegExp.exec(string)

This executes a search for a match in its string parameter. Unlike String.match, the parameter entered should be a string, not a regular expression pattern.

var pattern = /\d{4}/;

pattern.exec("today is 12-12-2000");

//returns array ["2000"]

String.replace(regular expression, replacement text)

This searches and replaces the regular expression portion (match) with the replaced text instead.

var phone = "(201) 123-4567";

var phoneFormatted = phone.replace(/[\(\)-\s]/g, "");

//returns 2011234567 (removed ( ) - and blank space)

String.split (string literal or regular expression)

This breaks up a string into an array of substrings, based on a regular expression or fixed string.

var oldstring = "1,2, 3, 4, 5";

var newstring = oldstring.split(/\s*,\s*/);

//returns the array ["1","2","3","4","5"]

String.search(regular expression)

This tests for a match in a string. It returns the index of the match, or -1, if it's not found.

var myString = "today is 12-12-2000";

myString.search(/\d{4}/);

//returns 15 - index of 2000

RegExp.test(string)

This tests whether the given string matches the Regexp, and returns true if it's matching, and false, if not.

var pattern = /\d{4}/;

pattern.test("today is 12-12-2000");

//returns true