A regular expression (instance) that determines the number \ Letter \ Chinese in JS _javascript tips

/*
To determine if the specified content is empty, or to eject the warning box if blank
*/
Function IsEmpty (thevalue, STRMSG) {
if (thevalue== "") {
Alert (strmsg+ "cannot be empty!");
return true;
}
return false;
}
/*
Chinese judgment function, allow rare words in English "*" instead
Returns true to indicate that it is eligible and returns false that does not conform
*/
function Ischinese (str) {
var Badchar = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Badchar + = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Badchar + = "0123456789";
Badchar + = "" + "";//Half-width and full-width spaces
Badchar + = "Www.jb51.net does not contain * or. English symbols
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);//character in string str
if (Badchar.indexof (c) >-1) {
return false;
}
}
return true;
}
/*
Numeric judgment function, returns true to be all numbers, and returns false to not all numbers
*/
function Isnumber (str) {
if ("" ==str) {
return false;
}
var reg =/\d/;
Return Str.match (reg) ==null;
}
/*
Determines whether a given string is a number of a specified length
is to return true, not return false
*/
function Isnumber_ex (Str,len) {
if ("" ==str) {
return false;
}
if (Str.length!=len) {
return false;
}
if (!isnumber (str)) {
return false;
}
return true;
}
/*
Money judgment function that allows the first one to "-" to represent a debt owed
Returns true to indicate that the format is correct and returns false for formatting errors
*/
function Ismoney (str) {
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);
if (i==0) {
if (c!= "-" && (c< "0" | | C> "9")) {
return false;
}else if (c==-"&&str.length==1") {
return false;
}
}else if (C < "0" | | | C > "9") {
return false;
}
}
return true;
}
/*
The English judgment function, returns True is all English, returns false to indicate not all is English
*/
function Isletter (str) {
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);
if (c< "a" | | C> "Z") && (c< "A" | | C> "Z")) {
return false;
}
}
return true;
}
/*
Space to judge, when containing a space to return false, when does not contain a space to return true
"" cannot be judged
*/
function Notinspace (str) {
if ("" ==str) {
return false;
}
var Badchar = "";
Badchar + = "";
for (var i=0;i var c = Str.charat (i);//character in string str
if (Badchar.indexof (c) >-1) {
return false;
}
}
return true;
}
/*
The * * Number judgment function, returns True is the * * number, returns false to indicate does not conform to the specification
*/
function Isfph (str) {
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);
if ((C < "0" | | | C > "9") && (c!= "-") && (c!= ",")) {
return false;
}
}
return true;
}
/*
A telephone judgment function that allows "number", ";", "-", "(", ")",
True indicates the phone number
*/
function Istelephone (str) {
var Truechar = "()-;1234567890";
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);//character in string str
if (Truechar.indexof (c) = =-1) return false;
}
return true;
}
/**
The academic system can be 1-7, or 3.5 of this form, not more than 7 years or less than 1 years
*/
function Isxz (str) {
if ("" ==str) {
return false;
}
var reg =/^[1-6] (\.5)? $/;
var r = Str.match (reg);
if (null!=r) {
return true;
}else{
if (str== "7") {
return true;
}else{
return false;
}
}
}
/*
To determine if the certificate number meets the requirements, the certificate number contains Chinese, numeric, uppercase and lowercase letters, (,),-
is to return true, not return false
*/
function ISZSBH (str) {
if ("" ==str) {
return false;
}
for (var i=0;i var c = Str.charat (i);
Alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Alpha + + "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Alpha + = "()-";
if (!ischinese (c) &&!isnumber (c)-&&alpha.indexof (c) ==-1) {
return false;
}
}
return true;
}
/*
Identity card function, is to return true, not return false
15 digits, 18 digits, or the last one is X (uppercase)
*/
function Issfz (str) {
if ("" ==str) {
return false;
}
if (str.length!=15&&str.length!=18) {//ID card length is incorrect
return false;
}
if (str.length==15) {
if (!isnumber (str)) {
return false;
}
}else{
STR1 = str.substring (0,17);
str2 = str.substring (17,18);
Alpha = "X0123456789";
if (!isnumber (str1) | | Alpha.indexof (STR2) ==-1) {
return false;
}
}
return true;
}
/*
Get today's year, month, day
Call Method: Today = new Gettoday (); Then today.year for today's year and so on
*/
function Gettoday () {
This.now = new Date ();
This.year = This.now.getFullYear ();
This.month = This.now.getMonth ();
This.day = This.now.getDate ();
}

JS judgment number, letter, Chinese
1.
var reg =/^ (\w|[ \U4E00-\U9FA5]) *$/;
if (Arr=username.match (REG))
{
Ti=1;
return ture;
}
Else
{
Alert ("User name is only allowed in English, numbers and Chinese characters, \ n Please check whether there are spaces or other symbols before and after");
ti=0;
return false;
}
2. Use regular expressions to restrict the entry of text boxes in a Web page's form:
The regular expression limit can only be entered in Chinese: onkeyup= "value=value.replace (/[^\u4e00-\u9fa5]/g,") "Onbeforepaste=" Clipboarddata.setdata (' Text ', Clipboarddata.getdata (' text '). Replace (/[^\u4e00-\u9fa5]/g, ') "
Only full-width characters can be entered with regular expression restrictions: onkeyup= "Value=value.replace (/[^\uff00-\uffff]/g,") "Onbeforepaste=" Clipboarddata.setdata (' Text ', Clipboarddata.getdata (' text '). Replace (/[^\uff00-\uffff]/g, ') "
Only numbers can be entered with regular expression restrictions: onkeyup= "Value=value.replace (/[^\d]/g,") "Onbeforepaste=" Clipboarddata.setdata (' text ', Clipboarddata.getdata (' text '). Replace (/[^\d]/g, ') "
Only numbers and English can be entered with regular expression restrictions: onkeyup= "Value=value.replace (/[\w]/g,") "Onbeforepaste=" Clipboarddata.setdata (' text ', Clipboarddata.getdata (' text '). Replace (/[^\d]/g, ') "

Digital
<script>
function Check ()
{
if (!isnan (Document.all.form.str.value))
{
Alert ("number");
}
</script>
Letters
<script>
function Check ()
{
var str =/[_a-za-z]/;
if (Str.test (Document.all.form.str.value))
{
Alert ("letter");
}
}
</script>
<form name= "form" action= "onsubmit=" return check (); " >
<input Type=text name=str>
<input type=submit>
<form>
---------------------------------------------------
/**
* Some common JavaScript functions (methods)
*
* methods that are written as string objects for ease of use
* Save him as a. js file, to facilitate the extension of the function of the string object
*
* Method Name function
* ----------- --------------------------------
* Trim Remove First space
* Occurs statistics the number of occurrences of the specified character
* Whether the IsDigit check is made up of numbers
* Isalpha Check whether it consists of a number of letters and underscores
* Isnumber Check whether the number
* LenB Returns the number of bytes
* Isinchinese Check whether Chinese characters are included
* Isemail Simple Email check
* IsDate a simple date check to successfully return the Date object
* Isinlist Check if there are characters in the list
* Isinlist Check if there are characters in the list
*/
/*** Remove the trailing space ***/
String.prototype.Trim = function () {
Return This.replace (/(^\s*) | ( \s*$)/g, "");
}
/*** count the number of occurrences of the specified character ***/
String.prototype.Occurs = function (ch) {
var re = eval ("/[^" +ch+ "]/g");
Return This.replace (Re, ""). Length;
return This.split (CH). Length-1;
}
/*** Check if it's made up of numbers ***/
String.prototype.isDigit = function () {
var s = this. Trim ();
Return (S.replace (/\d/g, ""). Length = = 0);
}
/*** Check to see if the numbers are composed of alphanumeric letters and underscores ***/
String.prototype.isAlpha = function () {
Return (This.replace (/\w/g, ""). Length = = 0);
}
/*** Check for a number of ***/
String.prototype.isNumber = function () {
var s = this. Trim ();
Return (S.search (/^[+-]?[ 0-9.]*$/) >= 0);
}
/*** returns the number of bytes ***/
String.prototype.lenb = function () {
Return This.replace (/[^\x00-\xff]/g, "* *"). Length;
}
/*** Check to see if Chinese characters are included ***/
String.prototype.isInChinese = function () {
Return (this.length!= this.replace (/[^\x00-\xff]/g, "* *"). length);
}
/*** Simple Email Check ***/
String.prototype.isEmail = function () {
var strr;
var mail = this;
var re =/(\w+@\w+\.\w+) (\.{ 0,1}\w*) (\.{ 0,1}\w*)/I;
re.exec (mail);
if (regexp.$3!= "" && regexp.$3!= "." && regexp.$2!= ".")
STRR = regexp.$1+regexp.$2+regexp.$3;
Else
if (regexp.$2!= "" && regexp.$2!= ".")
STRR = regexp.$1+regexp.$2;
Else
STRR = regexp.$1;
return (Strr==mail);
}
/*** a simple date check to successfully return a Date object ***/
String.prototype.isDate = function () {
var p;
var Re1 =/(\d{4}) [year./-] (\d{1,2}) [month./-] (\d{1,2}) [Day]?$/;
var Re2 =/(\d{1,2}) [month./-] (\d{1,2}) [Day./-] (\d{2}) [year]?$/;
var Re3 =/(\d{1,2}) [month./-] (\d{1,2}) [Day./-] (\d{4}) [year]?$/;
if (Re1.test (this)) {
p = re1.exec (this);
return new Date (P[1],p[2],p[3]);
}
if (Re2.test (this)) {
p = re2.exec (this);
return new Date (p[3],p[1],p[2]);
}
if (Re3.test (this)) {
p = re3.exec (this);
return new Date (p[3],p[1],p[2]);
}
return false;
}
/*** Check to see if there are any character characters in the list ***/
String.prototype.isInList = function (list) {
var re = eval ("/[" +list+ "]/");
Return Re.test (this);
}