Use regular expressions to validate/format a string
This is an impressive collection (that I found somehere on the Net) of various
functions to validate or format string in Javascript. The code is very compact.
/****************************************************************
FILE: RegExpValidate.js
DESCRIPTION: This file contains a library of validation functions
using javascript regular expressions. Library also contains
functions that reformat fields for display or for storage.
VALIDATION FUNCTIONS:
validateEmail - checks format of email address
validateUSPhone - checks format of US phone number
validateNumeric - checks for valid numeric value
validateInteger - checks for valid integer value
validateNotEmpty - checks for blank form field
validateUSZip - checks for valid US zip code
validateUSDate - checks for valid date in US format
validateValue - checks a string against supplied pattern
FORMAT FUNCTIONS:
rightTrim - removes trailing spaces from a string
leftTrim - removes leading spaces from a string
trimAll - removes leading and trailing spaces from a string
removeCurrency - removes currency formatting characters (), $
addCurrency - inserts currency formatting characters
removeCommas - removes comma separators from a number
addCommas - adds comma separators to a number
removeCharacters - removes characters from a string that match
passed pattern
AUTHOR: Karen Gayda
DATE: 03/24/2000
*******************************************************************/
function validateEmail( strValue) {
/************************************************
DESCRIPTION: Validates that a string contains a
valid email pattern.
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
REMARKS: Accounts for email with country appended
does not validate that email contains valid URL
type (.com, .gov, etc.) or valid country suffix.
*************************************************/
var objRegExp =
/(^[a-z]([a-z_\.]*)@([a-z_\.]*)([.][a-z]{3})$)|(^[a-z]([a-z_\.]*)@
([a-z_\.]*)(\.[a-z]{3})(\.[a-z]{2})*$)/i;
//check for valid email
return objRegExp.test(strValue);
}
function validateUSPhone( strValue ) {
/************************************************
DESCRIPTION: Validates that a string contains valid
US phone pattern.
Ex. (999) 999-9999 or (999)999-9999
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
*************************************************/
var objRegExp = /^\([1-9]\d{2}\)\s?\d{3}\-\d{4}$/;
//check for valid us phone with or without space between
//area code
return objRegExp.test(strValue);
}
function validateNumeric( strValue ) {
/*****************************************************************
DESCRIPTION: Validates that a string contains only valid numbers.
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
******************************************************************/
var objRegExp = /(^-?\d\d*\.\d*$)|(^-?\d\d*$)|(^-?\.\d\d*$)/;
//check for numeric characters
return objRegExp.test(strValue);
}
function validateInteger( strValue ) {
/************************************************
DESCRIPTION: Validates that a string contains only
valid integer number.
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
**************************************************/
var objRegExp = /(^-?\d\d*$)/;
//check for integer characters
return objRegExp.test(strValue);
}
function validateNotEmpty( strValue ) {
/************************************************
DESCRIPTION: Validates that a string is not all
blank (whitespace) characters.
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
*************************************************/
var strTemp = strValue;
strTemp = trimAll(strTemp);
if(strTemp.length > 0){
return true;
}
return false;
}
function validateUSZip( strValue ) {
/************************************************
DESCRIPTION: Validates that a string a United
States zip code in 5 digit format or zip+4
format. 99999 or 99999-9999
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
*************************************************/
var objRegExp = /(^\d{5}$)|(^\d{5}-\d{4}$)/;
//check for valid US Zipcode
return objRegExp.test(strValue);
}
function validateUSDate( strValue ) {
/************************************************
DESCRIPTION: Validates that a string contains only
valid dates with 2 digit month, 2 digit day,
4 digit year. Date separator can be ., -, or /.
Uses combination of regular expressions and
string parsing to validate date.
Ex. mm/dd/yyyy or mm-dd-yyyy or mm.dd.yyyy
PARAMETERS:
strValue - String to be tested for validity
RETURNS:
True if valid, otherwise false.
REMARKS:
Avoids some of the limitations of the Date.parse()
method such as the date separator character.
*************************************************/
var objRegExp = /^\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}$/
//check to see if in correct format
if(!objRegExp.test(strValue))
return false; //doesn't match pattern, bad date
else{
var strSeparator = strValue.substring(2,3)
var arrayDate = strValue.split(strSeparator);
//create a lookup for months not equal to Feb.
var arrayLookup = { '01' : 31,'03' : 31,
'04' : 30,'05' : 31,
'06' : 30,'07' : 31,
'08' : 31,'09' : 30,
'10' : 31,'11' : 30,'12' : 31}
var intDay = parseInt(arrayDate[1],10);
//check if month value and day value agree
if(arrayLookup[arrayDate[0]] != null) {
if(intDay <= arrayLookup[arrayDate[0]] && intDay != 0)
return true; //found in lookup table, good date
}
//check for February (bugfix 20050322)
//bugfix for parseInt kevin
//bugfix biss year O.Jp Voutat
var intMonth = parseInt(arrayDate[0],10);
if (intMonth == 2) {
var intYear = parseInt(arrayDate[2]);
if (intDay > 0 && intDay < 29) {
return true;
}
else if (intDay == 29) {
if ((intYear % 4 == 0) && (intYear % 100 != 0) ||
(intYear % 400 == 0)) {
// year div by 4 and ((not div by 100) or div by 400) ->ok
return true;
}
}
}
}
return false; //any other values, bad date
}
function validateValue( strValue, strMatchPattern ) {
/************************************************
DESCRIPTION: Validates that a string a matches
a valid regular expression value.
PARAMETERS:
strValue - String to be tested for validity
strMatchPattern - String containing a valid
regular expression match pattern.
RETURNS:
True if valid, otherwise false.
*************************************************/
var objRegExp = new RegExp( strMatchPattern);
//check if string matches pattern
return objRegExp.test(strValue);
}
function rightTrim( strValue ) {
/************************************************
DESCRIPTION: Trims trailing whitespace chars.
PARAMETERS:
strValue - String to be trimmed.
RETURNS:
Source string with right whitespaces removed.
*************************************************/
var objRegExp = /^([\w\W]*)(\b\s*)$/;
if(objRegExp.test(strValue)) {
//remove trailing a whitespace characters
strValue = strValue.replace(objRegExp, '$1');
}
return strValue;
}
function leftTrim( strValue ) {
/************************************************
DESCRIPTION: Trims leading whitespace chars.
PARAMETERS:
strValue - String to be trimmed
RETURNS:
Source string with left whitespaces removed.
*************************************************/
var objRegExp = /^(\s*)(\b[\w\W]*)$/;
if(objRegExp.test(strValue)) {
//remove leading a whitespace characters
strValue = strValue.replace(objRegExp, '$2');
}
return strValue;
}
function trimAll( strValue ) {
/************************************************
DESCRIPTION: Removes leading and trailing spaces.
PARAMETERS: Source string from which spaces will
be removed;
RETURNS: Source string with whitespaces removed.
*************************************************/
var objRegExp = /^(\s*)$/;
//check for all spaces
if(objRegExp.test(strValue)) {
strValue = strValue.replace(objRegExp, '');
if( strValue.length == 0)
return strValue;
}
//check for leading & trailing spaces
objRegExp = /^(\s*)([\W\w]*)(\b\s*$)/;
if(objRegExp.test(strValue)) {
//remove leading and trailing whitespace characters
strValue = strValue.replace(objRegExp, '$2');
}
return strValue;
}
function removeCurrency( strValue ) {
/************************************************
DESCRIPTION: Removes currency formatting from
source string.
PARAMETERS:
strValue - Source string from which currency formatting
will be removed;
RETURNS: Source string with commas removed.
*************************************************/
var objRegExp = /\(/;
var strMinus = '';
//check if negative
if(objRegExp.test(strValue)){
strMinus = '-';
}
objRegExp = /\)|\(|[,]/g;
strValue = strValue.replace(objRegExp,'');
if(strValue.indexOf('$') >= 0){
strValue = strValue.substring(1, strValue.length);
}
return strMinus + strValue;
}
function addCurrency( strValue ) {
/************************************************
DESCRIPTION: Formats a number as currency.
PARAMETERS:
strValue - Source string to be formatted
REMARKS: Assumes number passed is a valid
numeric value in the rounded to 2 decimal
places. If not, returns original value.
*************************************************/
var objRegExp = /-?[0-9]+\.[0-9]{2}$/;
if( objRegExp.test(strValue)) {
objRegExp.compile('^-');
strValue = addCommas(strValue);
if (objRegExp.test(strValue)){
strValue = '(' + strValue.replace(objRegExp,'') + ')';
}
return '$' + strValue;
}
else
return strValue;
}
function removeCommas( strValue ) {
/************************************************
DESCRIPTION: Removes commas from source string.
PARAMETERS:
strValue - Source string from which commas will
be removed;
RETURNS: Source string with commas removed.
*************************************************/
var objRegExp = /,/g; //search for commas globally
//replace all matches with empty strings
return strValue.replace(objRegExp,'');
}
function addCommas( strValue ) {
/************************************************
DESCRIPTION: Inserts commas into numeric string.
PARAMETERS:
strValue - source string containing commas.
RETURNS: String modified with comma grouping if
source was all numeric, otherwise source is
returned.
REMARKS: Used with integers or numbers with
2 or less decimal places.
*************************************************/
var objRegExp = new RegExp('(-?[0-9]+)([0-9]{3})');
//check for match to search criteria
while(objRegExp.test(strValue)) {
//replace original string with first group match,
//a comma, then second group match
strValue = strValue.replace(objRegExp, '$1,$2');
}
return strValue;
}
function removeCharacters( strValue, strMatchPattern ) {
/************************************************
DESCRIPTION: Removes characters from a source string
based upon matches of the supplied pattern.
PARAMETERS:
strValue - source string containing number.
RETURNS: String modified with characters
matching search pattern removed
USAGE: strNoSpaces = removeCharacters( ' sfdf dfd',
'\s*')
*************************************************/
var objRegExp = new RegExp( strMatchPattern, 'gi' );
//replace passed pattern matches with blanks
return strValue.replace(objRegExp,'');
}
You can try it here.
If you want to know more about these MSDN pages :
RegExp Object
Regular Expression Syntax
Common expressions
Date
/^\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}$/ mm/dd/yyyy
US zip code
/(^\d{5}$)|(^\d{5}-\d{4}$)/ 99999 or 99999-9999
Canadian postal code
/^\D{1}\d{1}\D{1}\-?\d{1}\D{1}\d{1}$/ Z5Z-5Z5 orZ5Z5Z5
Time
/^([1-9]|1[0-2]):[0-5]\d(:[0-5]\d(\.\d{1,3})?)?$/ HH:MM or HH:MM:SS or HH:MM:SS.mmm
IP Address(no check for alid values (0-255))
/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/ 999.999.999.999
Dollar Amount
/^((\$\d*)|(\$\d*\.\d{2})|(\d*)|(\d*\.\d{2}))$/ 100, 100.00, $100 or $100.00
Social Security Number
/^\d{3}\-?\d{2}\-?\d{4}$/ 999-99-9999 or999999999
Canadian Social Insurance Number
/^\d{9}$/ 999999999