StanSight

Validate Phone Number

Simple Phone number validation function that returns “true” if the phone number is in the format 555-555-5555

Useful when validating input from a form prior to writing it to a database.

(Note the use of regular expressions used to validate the formatting)

/**
*  This function validates that the provided string is a phone number with
*  the format of 555-555-5555
*
*  @param  s the String containing the phone number
*  @return boolean
*/
function isValidPhoneNumber(s) {

 // See if it is empty
 if (s.length == 0) {
  alert("Please enter a value for the phone number.");
  return false;
 }

 // Make Regular expression for checking for correct phone number format
 rePhoneNumber = new RegExp(/^[1-9]\d{2}\-\d{3}\-\d{4}$/);

 // Test string using regular expression (return false if it fails)
 if (!rePhoneNumber.test(s)) {
  alert("Phone Number Must Be Entered As: 555-555-5555");
  return false;
 }

 return true;
}