Undefined index error in php using ajax - php

Question

<form role="form" method="post" action="test.php">
<label for="contact">Mobile No:</label><br>
<input type="tel" class="form-control" name="contact" title="Mobile number should not contain alphabets. Maxlength 10" placeholder="Enter your phone no" maxlength="15" required id='contact_no'>
<br><br>
<button type="submit" class="btn btn-success" name="submit" id="submit">Submit</button>
<button type="reset" class="btn btn-default" id='reset'>Reset</button>
</form>
Ajax and Javascript Code
script type="text/javascript">
$(document).ready(function(){
$("#submit").click(function(){
var dialcode = $(".country-list .active").data().dialCode;
var contact = $("#contact_no").val().replace(" ","");
var countrycode = $('.country-list .active').data().countryCode;
var cn;
var cc;
var dc;
$.ajax({
url: "test.php",
type: "POST",
data: {'cc' : contact},
success: function(data)
{
alert("success");
}
});
});
});
</script>
The variables show the values if displayed by alert message but are not passed on to the test.php page. It shows undefined index error at the following statement
test.php is as follows
<?php
if(isset($_POST['submit'])){
$contact = $_POST['cc']; //it shows the error here
}
echo $contact;
I had referred to many websites which show the same thing. It dosent work for me. I think the syntz of ajax is correct and have tried all possibilities but still dosent work. Please help

Answer 1

You're posting {cc: contact}, but you're checking for $_POST['submit'] which isn't being sent. The callback also doesn't stop the event, so you might want to return false (stops default and propagation). Something like this should do the trick:
$('#submit').on('click', function()
{
//do stuff
$.ajax({
data: {cc: contact},
method: 'post',
success: function()
{
//handle response here
}
});
return false;
});
Then, in PHP:
if (isset($_POST['cc']))
{
//ajax request with cc data
}
Also not that this:
$("#contact_no").val().replace(" ","");
Will only replace 1 space, not all of them, for that you'll need to use a regex with a g (for global) flag:
$("#contact_no").val().replace(/\s+/g,"");

Answer 2

You are using ajax to form submit
and you use $_POST['submit'] to check it would be $_POST['cc']
test.php
<?php
if(isset($_POST['cc'])){// change submit to cc
$contact = $_POST['cc'];//it shows the error here
}
echo $contact;

Answer 3

#Saty answer worked for me, but my code on ajax was a bit different. I had multiple form data wrapped up into a form variable, that was passed to the php page.
const form = new FormData();
form.append('keywords', keywords);
form.append('timescale', timescale);
form.append('pricing_entered', pricing_entered);
$.ajax({
url: "../config/save_status.php",
data: form,
method: "POST",
datatype: "text",
success: function (response, data) {
}
Then my php was:
if (isset($_POST['data'])) {
// all code about database uploading
}