Js is not a basic knowledge

Js is not a basic Preface

Javascript is a very free language. Everything in Javascript is a variable, including a function.
Basic
Function
(Definition) (parameter 1 [, parameter 2...]) the following code creates a function and runs it.
(Function (str) {alert (str. length) ;}) ('test _ str ');

(Function (str1, str2) {alert (str1 str2) ;}) ('str111111', 'str222222 ');

Http://vc.wz: 80/l.html? Q = 5 & B = 5 # ddd
The first field (separated by space) Below is an attribute 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 expressions. One is to create an instance of a regular expression, but to use the regular expression related methods in the String object.
Var my_regex =/[a-z] +/g;
Var my_regex = new ("[a-z] +", "g ");

Exec (string), which is used to RegEx the string and returns the matching result.
Test (string) to test whether the string contains matching results
[Edit Regular Expressions in string objects] Regular Expressions in string objects

Match (pattern) performs regular match based on pattern. If it matches, the matching result is returned. If it does not match, null is returned.
Search (pattern) performs regular match based on pattern. If a result is matched, the number of indexes is returned; otherwise,-1 is returned.
Replace (pattern, replacement) performs regular matching based on pattern and replaces the matching result with replacement.
Split (pattern) performs regular segmentation based on pattern and returns a split array.