Your guess variable in the handle_event function is a string, so guess == socket.assigns.random is comparing a string against an integer. An easy fix would be to return a string from your random/0 function.

Bard said to make the handle_event like this,

  def handle_event("guess", %{"number" => guess}, socket) do
    message = cond do
      guess == socket.assigns.random ->
        "Your guess: #{guess}. Correct!"
        {:noreply, assign(socket, random: random())}
      true ->
        "Your guess: #{guess}. Wrong. Guess again."
    end

      {:noreply, assign(socket, score: socket.assigns.score + 1, message: message, time: time())}
    end

but that didn’t work either.

Thank you for your reply!

It doesn’t work. I tried converting the value inside random() function to String, it didn’t work that way.
Then I converted the guess coming from the user inside the handle_event to integer before comparing it with socket.assign.random, it didn’t work again.

Right now my code is as follows,

defmodule PentoWeb.WrongLive do
  use PentoWeb, :live_view

  def mount(_params, _session, socket) do
    {:ok, assign(socket, score: 0, message: "Make a guess:", time: time(), random: random())}
  end

  def render(assigns) do
    ~H"""
    <h1 class="mb-4 text-4xl font-extrabold">Your score: <%= @score %></h1>
    <h2>
      <%= @message %>
      The randome number is <%= @random %>
    </h2>
    <br/>
    <h2>
      <%= for n <- 1..10 do %>
        <.link class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 border border-blue-700 rounded m-1" phx-click="guess" phx-value-number= {n} >
          <%= n %>
        </.link>
      <% end %>
    </h2>
    """
  end

  def time() do
    DateTime.utc_now()
  end

  def random() do
    Enum.random(1..10)
  end

  def handle_event("guess", %{"number" => guess}, socket) do
    guess = Integer.parse(guess) |> elem(0)
    message = cond do
      guess == socket.assigns.random ->
        "Your guess: #{guess}. Correct!"
        {:noreply, assign(socket, random: random())}
      true ->
        "Your guess: #{guess}. Wrong. Guess again."
    end

      {:noreply, assign(socket, score: socket.assigns.score + 1, message: message, time: time())}
    end
  end

At this point when I click the correct option, it gives the following error,

[debug] HANDLE EVENT "guess" in PentoWeb.WrongLive
  Parameters: %{"number" => "3"}
[debug] Replied in 729µs
[error] GenServer #PID<0.505.0> terminating
** (Protocol.UndefinedError) protocol Phoenix.HTML.Safe not implemented for {:noreply, #Phoenix.LiveView.Socket<id: "phx-F5RYrXnIuZbLRwBE", endpoint: PentoWeb.Endpoint, view: PentoWeb.WrongLive, parent_pid: nil, root_pid: #PID<0.505.0>, router: PentoWeb.Router, assigns: %{message: "Make a guess:", time: ~U[2023-11-04 06:49:57.476986Z], random: 2, __changed__: %{random: true}, flash: %{}, live_action: nil, score: 0}, transport_pid: #PID<0.497.0>, ...>} of type Tuple. This protocol is implemented for the following type(s): Atom, BitString, Date, DateTime, Decimal, Float, Integer, List, NaiveDateTime, Phoenix.HTML.Form, Phoenix.LiveComponent.CID, Phoenix.LiveView.Component, Phoenix.LiveView.Comprehension, Phoenix.LiveView.JS, Phoenix.LiveView.Rendered, Time, Tuple, URI
    (phoenix_html 3.3.3) lib/phoenix_html/safe.ex:97: Phoenix.HTML.Safe.Tuple.to_iodata/1
    (pento 0.1.0) lib/pento_web/live/wrong_live.ex:12: anonymous fn/2 in PentoWeb.WrongLive.render/1
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/diff.ex:363: Phoenix.LiveView.Diff.traverse/7
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/diff.ex:538: anonymous fn/4 in Phoenix.LiveView.Diff.traverse_dynamic/7
    (elixir 1.15.7) lib/enum.ex:2510: Enum."-reduce/3-lists^foldl/2-0-"/3
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/diff.ex:361: Phoenix.LiveView.Diff.traverse/7
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/diff.ex:136: Phoenix.LiveView.Diff.render/3
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/channel.ex:833: Phoenix.LiveView.Channel.render_diff/3
    (phoenix_live_view 0.19.5) lib/phoenix_live_view/channel.ex:689: Phoenix.LiveView.Channel.handle_changed/4
    (stdlib 5.1.1) gen_server.erl:1077: :gen_server.try_handle_info/3
    (stdlib 5.1.1) gen_server.erl:1165: :gen_server.handle_msg/6
    (stdlib 5.1.1) proc_lib.erl:251: :proc_lib.wake_up/3
Last message: %Phoenix.Socket.Message{topic: "lv:phx-F5RYrXnIuZbLRwBE", event: "event", payload: %{"event" => "guess", "type" => "click", "value" => %{"number" => "3"}}, ref: "13", join_ref: "11"}
State: %{socket: #Phoenix.LiveView.Socket<id: "phx-F5RYrXnIuZbLRwBE", endpoint: PentoWeb.Endpoint, view: PentoWeb.WrongLive, parent_pid: nil, root_pid: #PID<0.505.0>, router: PentoWeb.Router, assigns: %{message: "Make a guess:", time: ~U[2023-11-04 06:49:57.476986Z], random: 3, __changed__: %{}, flash: %{}, live_action: nil, score: 0}, transport_pid: #PID<0.497.0>, ...>, components: {%{}, %{}, 1}, topic: "lv:phx-F5RYrXnIuZbLRwBE", serializer: Phoenix.Socket.V2.JSONSerializer, join_ref: "11", upload_names: %{}, upload_pids: %{}}
[debug] MOUNT PentoWeb.WrongLive
  Parameters: %{}
  Session: %{"_csrf_token" => "-UTX1GiHNYDm90jd4qqktPfh"}
[debug] Replied in 104µs