WebService : http://localhost/register.php

response : {"status":1,"message":"User already existed with armalsandip@gmail.com"}

<?php

require_once 'include/DB_Functions.php';
$db = new DB_Functions();

// json response array
$response = array("status" => 1);

if (isset($_POST['name']) && isset($_POST['email']) && isset($_POST['password']) && isset($_POST['number'])) {

    // receiving the post params
    $name = $_POST['name'];
    $email = $_POST['email'];
    $password = $_POST['password'];
    $number = $_POST['number'];

    // check if user is already existed with the same email
    if ($db->isUserExisted($email)) {
        // user already existed
        $response["status"] = 1;
        $response["message"] = "User already existed with " . $email;
        echo json_encode($response);
    } else {
        // create a new user
        $user = $db->storeUser($name, $email, $password, $number);
        if ($user) {
            // user stored successfully
            $response["status"] = 0;
            $response["id"] = $user["id"];
            $response["user"]["name"] = $user["name"];
            $response["user"]["email"] = $user["email"];
            $response["message"] = "User registered successfully with " . $email;
            echo json_encode($response);
        } else {
            // user failed to store
            $response["status"] = 2;
            $response["message"] = "Unknown error occurred in registration!";
            echo json_encode($response);
        }
    }
} else {
    // receiving the post params
    $response["status"] = 3;
    $response["message"] = "Required parameters (name, email or password) is missing!";
    echo json_encode($response);
}
?>

public function storeUser($name, $email, $password, $number) {
    $hash = $this->hashSSHA($password);
    $encrypted_password = $hash["encrypted"]; // encrypted password
    $salt = $hash["salt"]; // salt

    $stmt = $this->conn->prepare("INSERT INTO users( name, email, number, encrypted_password, salt, created_at) VALUES(?, ?, ?, ?, ?, NOW())");
    $stmt->bind_param("sssss", $name, $email, $number, $encrypted_password, $salt);
    $result = $stmt->execute();
    $stmt->close();

    // check for successful store
    if ($result) {
        $stmt = $this->conn->prepare("SELECT * FROM users WHERE email = ?");
        $stmt->bind_param("s", $email);
        $stmt->execute();
        $user = $stmt->get_result()->fetch_assoc();
        $stmt->close();

        return $user;
    } else {
        return false;
    }
}

 public function isUserExisted($email) {
    $stmt = $this->conn->prepare("SELECT email from users WHERE email = ?");

    $stmt->bind_param("s", $email);

    $stmt->execute();

    $stmt->store_result();

    if ($stmt->num_rows > 0) {
        // user existed
        $stmt->close();
        return true;
    } else {
        // user not existed
        $stmt->close();
        return false;
    }
}