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,$2'); } return strValue; } function removeCharacters( strValue, strMatchPattern ) { /************************************************ DESCRIPTION: Removes characters from a source string based upon matches of the supplied pattern. PARAMETERS: strValue - source string containing number. RETURNS: String modified with characters matching search pattern removed USAGE: strNoSpaces = removeCharacters( ' sfdf dfd', '\s*') *************************************************/ var objRegExp = new RegExp( strMatchPattern, 'gi' ); //replace passed pattern matches with blanks return strValue.replace(objRegExp,''); }If you want to know more about these MSDN pages :
RegExp Object
Regular Expression Syntax
Common expressions
Date /^\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}$/ 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}$/ 999999999special characters check [%\'\\\\]
