The regexp in JavaScript

Regular expressions are a set of independent rules that almost every programming language provides classes that implement these rules

1. Create a regular object in two ways

The first method of creation:

var reg = new RegExp (pattern,flags);

Second method of Creation (recommended):

var reg =/pattern/flags;//flags If is g, indicates global match, if I, the case is ignored

2. Two common methods

Method	Role
Test ()	Tests if a piece of text matches this regular expression Retrieves the specified value in a string. The return value is true or false.
EXEC ()	You can get a portion of text that matches a regular match (the return value is an array or null) The return value is the value that was found. If no match is found, NULL is returned.

3. Example

(1) Identify each matching item

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >
650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M00/86/9F/wKioL1fFpR_x78CIAAGpJMuVDgM508.gif "title=" Find each matching item. gif "alt=" Wkiol1ffpr_x78ciaagpjmuvdgm508.gif "/>

(2) Find out all mobile phone numbers
<! doctype html public  "-//w3c//dtd html 4.01 transitional//en"   "HTTP// Www.w3.org/TR/html4/loose.dtd ">
650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M01/86/A0/wKiom1fFpb-R0TwVAAHH9SgaYZc680.gif "title=" Find out all mobile phone numbers. gif "alt=" Wkiom1ffpb-r0twvaahh9sgayzc680.gif "/>

(3) Replace All
<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >
650) this.width=650; "src=" Http://s2.51cto.com/wyfs02/M01/86/9F/wKioL1fFpmqyd9i_AAFh8K02vTg533.gif "title=" Replace all. gif "alt=" Wkiol1ffpmqyd9i_aafh8k02vtg533.gif "/>

(4) Verifying the mailbox format
<! doctype html public  "-//w3c//dtd html 4.01 transitional//en"   "HTTP// Www.w3.org/TR/html4/loose.dtd ">
650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M01/86/A0/wKiom1fFqOuB8utEAADQMPHGq-4305.gif "title=" Verify the mailbox format 2.gif "alt=" Wkiom1ffqoub8uteaadqmphgq-4305.gif "/>


The regexp in JavaScript