RegExp Pattern Matching +location page Jump +cookie/localstorage Local Storage

In the process of learning JS, according to the knowledge points to write some code to test, in order to verify.

This procedure uses the following knowledge points:

1.regexp, pattern matching of data

2. Use the Location object for page jumps.

Use of local storage such as 3.cookie/localstorage

<! DOCTYPE html> for= "Inp1" id= "Label1" >User name:<input id= "INP1" type= "text" placeholder= "username" ></label><br/><label for= "Inp2" id= "Label2" >Password:<input id= "inp2" type= "password" placeholder= "password" ></label><br/><button id= "btn1" onclick = "JData ()" >submit</button><script type= "Text/javascript" >varSpan1=document.getelementbyid ("Span1"); varInp1=document.getelementbyid ("Inp1"); varInp2=document.getelementbyid ("Inp2"); functionJData (ID) {//Verify user name: Only 1-30 strings beginning with a letter can be entered        varpatt1=NewREGEXP (/^[a-z][a-za-z0-9_-]{0,29}/, "G"); //Check Password: Only 6-20 letters, numbers, underscores can be entered        varPatt2=NewREGEXP (/[a-za-z0-9_]{6,20}/, "G"); varRes=patt1.test (Inp1.value) &&patt2.test (Inp2.value); if(res) {//window.location.href= "http://www.baidu.com";Window.location.assign ("http://www.baidu.com");//Window.event.returnValue = false;}Else{span1.innerhtml= "Username or password wrong"; }    }</script></body>
1.regexp notes
A.[] and meta data
1) [character] understood as the opposite bracket specific content matches
2)., \w, \d, understood to be a kind of a wildcard
B. quantifiers
n+; at least once/once and above
N. Any time
N?;0 Times or 1 times
n{}; This specified number of times: n{x};x Times
N{x,y} times can be between x~y
N{x,} at least x times × times and above

^n; start with n
n$; end With N
RegExp Pattern Matching +location page Jump +cookie/localstorage Local Storage