Javascript U.S.A. Phone Number Validation

U.S.A. Phone Number Validation - Using Javascript

When collecting user phone numbers using forms in the website, it is a good idea to use client side validation along with your server side validation. The following example shows how you can validate US phone numbers using javascript.

We have also provided the javascript validation code for the International Phone Number validation, specially for North America Phone number validation and General Phone Number validation using javascipt regular expression.

Example

Example of USA Phone Number Validation

View Explanation of the Code

Cut and Paste Code

Cut 'n' paste code for the above Example

JavaScript Code

/**

* DHTML phone number validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)

// Declaring required variables

var digits = "0123456789";

// non-digit characters which are allowed in phone numbers

var phoneNumberDelimiters = "()- ";

// characters which are allowed in international phone numbers

// (a leading + is OK)

var validWorldPhoneChars = phoneNumberDelimiters + "+";

// Minimum no of digits in an international phone no.

var minDigitsInIPhoneNumber = 10;

// Maximum no of digits in an america phone no.

var maxDigitsInIPhoneNumber = 13;

//US Area Code

var AreaCode=new Array(205,251,659,256,334,907,403,780,264,268,520,928,480,602,623,501,479,870,242,246,441,250,604,778,284,341,442,628,657,669,747,752,764,951,209,559,408,831,510,213,310,424,323,562,707,369,627,530,714,949,626,909,916,760,619,858,935,818,415,925,661,805,650,600,809,345,670,211,720,970,303,719,203,475,860,959,302,411,202,767,911,239,386,689,754,941,954,561,407,727,352,904,850,786,863,305,321,813,470,478,770,678,404,706,912,229,710,473,671,808,208,312,773,630,847,708,815,224,331,464,872,217,618,309,260,317,219,765,812,563,641,515,319,712,876,620,785,913,316,270,859,606,502,225,337,985,504,318,318,204,227,240,443,667,410,301,339,351,774,781,857,978,508,617,413,231,269,989,734,517,313,810,248,278,586,679,947,906,616,320,612,763,952,218,507,651,228,601,557,573,636,660,975,314,816,417,664 ,406,402,308,775,702,506,603,551,848,862,732,908,201,973,609,856,505,575,585,845,917,516,212,646,315,518,347 ,718,607,914,631,716,709,252,336,828,910,980,984,919,704,701,283,380,567,216,614,937,330,234,440,419,740,513 ,580,918,405,905,289,647,705,807,613,519,416,503,541,971,445,610,835,878,484,717,570,412,215,267,814,724,902,787,939,438,450,819,418,514,401,306,803,843,864,605,869,758,784,731,865,931,423,615,901,325,361,430,432,469,682,737,979,214,972,254,940,713,281,832,956,817,806,903,210,830,409,936,512,915,868,649,340,385,435,801,802,276,434,540,571,757,703,804,509,206,425,253,360,564,304,262,920,414,715,608,307,867)

function isInteger(s)

{   var i;

for (i = 0; i < s.length; i++)

{

// Check that current character is number.

var c = s.charAt(i);

if (((c < "0") || (c > "9"))) return false;

}

// All characters are numbers.

return true;

}

function stripCharsInBag(s, bag)

{   var i;

var returnString = "";

// Search through string's characters one by one.

// If character is not in bag, append to returnString.

for (i = 0; i < s.length; i++)

{

// Check that current character isn't whitespace.

var c = s.charAt(i);

if (bag.indexOf(c) == -1) returnString += c;

}

return returnString;

}

function trim(s)

{   var i;

var returnString = "";

// Search through string's characters one by one.

// If character is not a whitespace, append to returnString.

for (i = 0; i < s.length; i++)

{

// Check that current character isn't whitespace.

var c = s.charAt(i);

if (c != " ") returnString += c;

}

return returnString;

}

function checkInternationalPhone(strPhone){

strPhone=trim(strPhone)

if(strPhone.indexOf("00")==0) strPhone=strPhone.substring(2)

if(strPhone.indexOf("+")>1) return false

if(strPhone.indexOf("+")==0) strPhone=strPhone.substring(1)

if(strPhone.indexOf("(")==-1 && strPhone.indexOf(")")!=-1)return false

if(strPhone.indexOf("(")!=-1 && strPhone.indexOf(")")==-1)return false

s=stripCharsInBag(strPhone,validWorldPhoneChars);

if(strPhone.length>10){var CCode=s.substring(0,s.length-10);}

else{CCode="";}

if(strPhone.length>7){var NPA=s.substring(s.length-10,s.length-7);}

else{NPA=""}

var NEC=s.substring(s.length-7,s.length-4)

if(CCode!="" && CCode!=null){

if(CCode!="1" && CCode!="011" && CCode!="001") return false

}

if(NPA!=""){

if(checkAreaCode(NPA)==false){ //Checking area code is vaid or not

return false

}

else{return false}

return (isInteger(s) && s.length >= minDigitsInIPhoneNumber  &&  s.length <= maxDigitsInIPhoneNumber );

}

//Checking area code is vaid or not

function checkAreaCode(val){

var res=false;

for (var i=0; i<AreaCode.length;i++){

if(AreaCode[i]==val) res=true;

}

return res

}

function ValidateForm(){

var Phone=document.frmSample.txtPhone

if ((Phone.value==null)||(Phone.value=="")){

alert("Please Enter your Phone Number")

Phone.focus()

return false

}

if (checkInternationalPhone(Phone.value)==false){

alert("Please Enter a Valid Phone Number")

Phone.value=""

Phone.focus()

return false

}

return true

}

</script>

HTML Code

Explanation of the Code

The JavaScript has the following main functions:

Function checkInternationalPhone is used to verify if the given value is a possible valid international phone number : This function first removes all non-digit characters which are allowed in phone numbers. These delimiters are declared in the lines (found in the beginning of the code) :

var phoneNumberDelimiters = "()- "
var validWorldPhoneChars = phoneNumberDelimiters + "+"
var AreaCode =newArray(205,251,659,256,334,907,403,780,264,268,520,928,480,602,623,501,479,870,242,246,441,
250,604,778,284,341,442,628,657,669,747,752,764,951,209,559,408,831,510,213,310,424,323,562,707,369,627,
530,714,949,626,909,916,760,619,858,935,818,415,925,661,805,650,600,809,345,670,211,720,970,303,719,203,
475,860,959,302,411,202,767,911,239,386,689,754,941,954,561,407,727,352,904,850,786,863,305,321,813,470,
478,770,678,404,706,912,229,710,473,671,808,208,312,773,630,847,708,815,224,331,464,872,217,618,309,260,317,
219,765,812,563,641,515,319,712,876,620,785,913,316,270,859,606,502,225,337,985,504,318,318,204,227,240,443,
667,410,301,339,351,774,781,857,978,508,617,413,231,269,989,734,517,313,810,248,278,586,679,947,906,616,320,
612,763,952,218,507,651,228,601,557,573,636,660,975,314,816,417,664,406,402,308,775,702,506,603,551,848,862,
732,908,201,973,609,856,505,575,585,845,917,516,212,646,315,518,347,718,607,914,631,716,709,252,336,828,910,
980,984,919,704,701,283,380,567,216,614,937,330,234,440,419,740,513,580,918,405,905,289,647,705,807,613,519,
416,503,541,971,445,610,835,878,484,717,570,412,215,267,814,724,902,787,939,438,450,819,418,514,401,306,803,
843,864,605,869,758,784,731,865,931,423,615,901,325,361,430,432,469,682,737,979,214,972,254,940,713,281,832,
956,817,806,903,210,830,409,936,512,915,868,649,340,385,435,801,802,276,434,540,571,757,703,804,509,206,425,
253,360,564,304,262,920,414,715,608,307,867)

Now that all valid delimiters are removed we just check if the remaining value is an integer and that it has at least a certain number of digits (given by the variable 'minDigitsInIPhoneNumber').
Function ValidateForm is used to make sure that the phone number field is not blank and the area code should be in areacode array variable and maximum digits should be 10 digits .that it is a valid phone number on form submission

U.S.A. Phone Number Validation