JS is not the foundation of basic knowledge

Objective

JavaScript is a very free language, in JS, everything inside is a variable. including functions.
Basis
Function
Definition (parameter 1[, Parameter 2..]) The following code creates a function and executes it.
(function (str) {alert (str.length);}) (' Test_str ');

(function (STR1,STR2) {alert (str1 str2);}) (' str1111 ', ' str2222 ');

Http://vc.wz:80/l.html?q=5&b=5#ddd
The first field (the field is separated by a space) is one of the properties of Window.location, followed by its value.
Hash #ddd
Host VC.WZ:80
Hostname Vc.wz
href http://vc.wz/l.html?q=5

In JavaScript, there are two ways to use regular methods, one is to create an instance of a regular expression, but rather to use a regular expression in a string object to relate the method.
var my_regex=/[a-z]+/g;
var my_regex=new ("[a-z]+", "G");

EXEC (string), which is regular processing of a string and returns the result of the match.
Test (string), which tests whether a string contains a matching result
Regular in a regular string object in an Edit string object

Match (pattern) is a regular match based on pattern and, if matched to, returns a matching result, such as a match that does not return null
Search (pattern) is a regular match according to pattern, if the match to a result, then return its index number; otherwise return-1
Replace (pattern,replacement) is a regular match based on pattern, and the matching result is replaced by replacement
Split (pattern) is a regular segment based on pattern, which returns a segmented array.