CRUD for .json file

delete-json.cs

private void Delete(string Customer)
{
  // not tested
    var array = Read().Item1;
    var path = Read().Item2;

    array.RemoveAt(array.FindIndex(x => x.Customer.Equals(Customer)));

    string jsonData = JsonConvert.SerializeObject(array);
    File.WriteAllText(path, jsonData);
}

find-json.cs

private CustomerMapLocations Find(string Customer)
{
    var array = ReadJson().Item1;
    var customer = array.Where(c => c.Customer.Equals(Customer)).FirstOrDefault();

    return customer;
}

read-json.cs

private Tuple<List<CustomerMapLocations>, string> Read()
{
    // get base directory
    var dir = AppDomain.CurrentDomain.BaseDirectory;
    string path = $"{dir}/addresses.json";
            
    //deserialize JSON from file  
    string Json = System.IO.File.ReadAllText(path);
    JavaScriptSerializer ser = new JavaScriptSerializer();
    var array = ser.Deserialize<List<CustomerMapLocations>>(Json);

    return Tuple.Create(array, path);
}

update-json.cs

private void Update(string Customer, double Long, double Lat)
{
    var array = ReadJson().Item1;
    var path = ReadJson().Item2;

    array.Add(new CustomerMapLocations { Customer = Customer, Latitude = Lat, Longitude = Long });

    string jsonData = JsonConvert.SerializeObject(array);
    File.WriteAllText(path, jsonData);
}