I would like NOT to add the same value to local Storage ( javaScript)

enter image description here I am new in code. Please help. i am saving inputs to local storage. I input several todo list like sleep, shopping, study, joggingAss you see on picture, there are 2 sleep. You can see in picture. I would like ti write alert when i input the same todo. like not to input sleep or shopping twice.

const newtodo = document.querySelector("#todo")  const form = document.querySelector("#todo-form");    form.addEventListener("submit", addtodoToLocalStorage);      function addtodoToLocalStorage(e) {      const value = newtodo.value;    let todos;    if (localStorage.getItem("input") === null) {        todos = [];    }    else {      todos = JSON.parse(localStorage.getItem("input"))    }      todos.push(value);    localStorage.setItem("input", JSON.stringify(todos))    newtodo.value = "";        e.preventDefault();  }  

https://stackoverflow.com/questions/65546260/i-would-like-not-to-add-the-same-value-to-local-storage-javascript January 03, 2021 at 11:00AM