Question

This phone number validator doesn’t work :/. Why?

Ideally, if the optional phone field is not null, it should proceed to validate the form.

The phone field is optional, and isn’t required.

Validating the form:

• the phone field is optional. this means that it is not required.
• it should ignore comparing everything except numbers.
• if the digit count is != 10 numbers, it should display the error.
• if the count is equal to 10 digits, it should pass onto name.php (see the HTML)

---

Javascript Code:

function validateForm() {
var x=document.forms["form"]["name"].value;
if (x==null || x=="")
  {
  alert("Name is required.");
  return false;
  }

var y=document.forms["form"]["email"].value;
var atpos=y.indexOf("@");
var dotpos=y.lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=y.length)
  {
    alert("Valid email required.");
    return false;
  }

var formValue = document.forms["form"]["number"].value;
var regExpressionValue = /[^\d.]/g;
if (formValue !== null)
{
  if (regExpressionValue.test(formValue) !== true)
  {
    alert("Optional phone number invalid. Example: [1234567890].");
    return false;
  }
}

return true;

}

---

HTML:

<form class="form" id="form" name="form" method="post" action="name.php" onsubmit="return validateForm()" />
<input type="text" name="name" id="name" />
<input type="text" name="email" id="email" />
<input type="tel" name="number" id="number" />
<button type="submit" value="Send" />Sign Up</button>
<div class="spacer"></div>
</form>

Answer 1

You have bad regexp and string presence check for phone number. Check this out:

function validateForm() {
   var x=document.forms["form"]["name"].value;
   if (x==null || x=="")
   {
     alert("Name is required.");
     return false;
   }

  var y=document.forms["form"]["email"].value;
  var atpos=y.indexOf("@");
  var dotpos=y.lastIndexOf(".");
  if (atpos<1 || dotpos<atpos+2 || dotpos+2>=y.length)
   {
     alert("Valid email required.");
     return false;
   }
  var formValue = document.forms["form"]["number"].value;
  if (formValue)
  {
  var regExpressionValue = /^(\d-?){10}$/g;
    if (regExpressionValue.test(formValue) !== true)
    {
      alert("Optional phone number invalid. Example: [1234567890].");
      return false;
   }
 }

return true;
}