JavaScript validates character numbers of Chinese characters, etc.

An example of validating a user name:

Html:

<input type= "text" value= "" name= "username" id= "username" onblur= "checkUser ()"/><span id= "Usertips" >< /SPAN>

Js:

function CheckUser ()

{

var username = $ ("#username"). Val ();

if (!username.match (/^[\u4e00-\u9fa5a-za-z0-9_]{3,20}$/)) {var msg = "Kanji alphanumeric underscore consisting of 3-20 bits"; $ ("#usertips"). HTML (MSG) ; } else {$ ("#usertips"). html (');}}

1, only allow input digital <input name= "username" type= "text" onkeyup= "Value=this.value.replace (/\d+/g, ')" >
2, only allow the input of English letters, numbers and underscores (the following two ways to achieve) <input name= "username" type= "text" style= "ime-mode:disabled" > <input name= "u Sername "type=" text "onkeyup=" Value=value.replace (/[^\w\.\/]/ig, ') ">
3, only allow the input of English letters, numbers and [email protected]# <input name= "username" type= "text" onkeyup= "Value=value.replace (/[^\[email Protected]#]|_/ig, ') ' >
4, only allow input Chinese characters <input name= "username" type= "text" onkeyup= "Value=value.replace (/[^\u4e00-\u9fa5]/g, ')" > 1, only allowed to enter the number <input name= "username" type= "text" onkeyup= "Value=this.value.replace (/\d+/g, ')" >
2, only allow the input of English letters, numbers and underscores (the following two ways to achieve) <input name= "username" type= "text" style= "ime-mode:disabled" > <input name= "u Sername "type=" text "onkeyup=" Value=value.replace (/[^\w\.\/]/ig, ') ">
3, only allow the input of English letters, numbers and [email protected]# <input name= "username" type= "text" onkeyup= "Value=value.replace (/[^\[email Protected]#]|_/ig, ') ' >
4, only allow input Chinese characters <input name= "username" type= "text" onkeyup= "Value=value.replace (/[^\u4e00-\u9fa5]/g, ')" >

Only numbers can be entered: "^[0-9]*$". Only n digits can be entered: "^\d{n}$".

Only numbers with at least n digits can be entered: "^\d{n,}$". You can enter only the digits of the m~n bit:. "^\d{m,n}$"

Only numbers starting with 0 and non-0 can be entered: "^ (0|[ 1-9][0-9]*) $ ".

You can only enter a positive real number with two decimal places: "^[0-9]+ (. [ 0-9]{2})? $ ".

You can only enter a positive real number with a decimal position: "^[0-9]+ (. [ 0-9]{1,3})? $ ".

You can only enter a non-zero positive integer: "^\+?" [1-9] [0-9]*$]. You can only enter a non-zero negative integer: "^\-[1-9][]0-9" *$.

Only characters with a length of 3 can be entered: "^. {3}$ ". You can only enter a string consisting of 26 English letters: "^[a-za-z]+$".

You can only enter a string consisting of 26 uppercase English letters: "^[a-z]+$". You can only enter a string consisting of 26 lowercase English letters: "^[a-z]+$".

You can only enter a string consisting of a number and 26 English letters: "^[a-za-z0-9]+$".

You can only enter a string consisting of a number, 26 letters, or underscores: "^\w+$". Verify user password: "^[a-za-z]\w{5,17}$" is in the correct format: Beginning with letter, length between 6~18,

Only characters, numbers, and underscores can be included. Verify that it contains ^%& ',; =?$\ ' characters: "[^%& ',; =?$\x22]+".

Only Chinese characters can be entered: "^[\u4e00-\u9fa5]{0,}$"

JavaScript validates character numbers of Chinese characters, etc.