Ajax request in cordova not working - php

Question

I am using ajax request to a php script in order to registrate a new user, it works and saves it in the database, but returns as error and not as success.
This is my ajax request:
$.ajax({
type: "POST",
url: "http://localhost/webAPI/register.php",
data: dataString,
crossDomain: true,
cache: false,
success: function (data) {
if (data == 1)
alert("success");
else(data == 0 )
alert("error");
},
error: function (){
alert("An Error Ocurred");
}
});
and this is my php script:
if($_POST)
{
$user_name = $_POST['username'];
$user_password = $_POST['password'];
$joining_date = date('Y-m-d H:i:s');
//password_hash see : http://www.php.net/manual/en/function.password-hash.php
$password = password_hash( $user_password, PASSWORD_BCRYPT, array('cost' => 11));
//if($count==0){
$stmt = $db_con->prepare("INSERT INTO users(username,password,joiningdate) VALUES(:uname,:pass,:jdate)");
$stmt->bindParam(":uname",$user_name);
$stmt->bindParam(":pass",$user_password);
$stmt->bindParam(":jdate",$joining_date);
if($stmt->execute())
{
echo 1;
}
else
{
echo 0;
}
}

Answer 1

replace else(data == 0 ) with else
$.ajax({
type: "POST",
url: "http://localhost/webAPI/register.php",
data: dataString,
crossDomain: true,
cache: false,
success: function (data) {
if (data == 1)
alert("success");
else
alert("error");
},
error: function (){
alert("An Error Ocurred");
}
});
and in PHP code
if($stmt->execute())
{
exit(1);
}
else
{
exit(0);
}

Answer 2

You could parse the PHP response in JSON in order to check the result from JS.
The PHP response :
if ($stmt->execute()) {
die(json_encode(['return' => true]));
} else {
die(json_encode(['return' => false]));
}
And from JS, just check the return flag :
$.ajax({
type: "POST",
url: "http://localhost/webAPI/register.php",
data: dataString,
dataType: 'JSON', // tell JS that the PHP response is json formated
crossDomain: true,
cache: false,
success: function (data) {
if (data.return) { // check if return is true
alert("success");
} else { // if return is false
alert("error");
}
},
error: function (jqXHR, textStatus, errorThrown){
console.log(textStatus, errorThrown); // this will tell you more in case of unsuccessful request
}
});
Hope it helps.
EDIT :
Look at the Ajax error attribute function. It must tell you more about the error.
RE-EDIT :
The dataString you send to PHP must be a JSON object. So from your comment, it must look like :
var dataString = {
username: $("#username").val(),
password: $("#password").val()
};

Answer 3

The only problem was the missing datatype property in the ajax request.