script.js

const inputBox=document.getElementById("input-box");
const listContainer=document.getElementById("list-container");
function addTask(){
    if(inputBox.value === ''){
        alert('Please enter a task');
    }
    else{
        let li = document.createElement("li");
        li.innerHTML=inputBox.value;
        listContainer.appendChild(li);
        let span=document.createElement("span");
        span.innerHTML="\u00d7";
        li.appendChild(span);
    }
    inputBox.value="";
    saveData();
}

listContainer.addEventListener("click",function(e){
    if (e.target.tagName==="LI"){
        e.target.classList.toggle("checked");     
        saveData(); 
    }
else if(e.target.tagName === "SPAN"){
e.target.parentElement.remove();
saveData();
}
},false);
function saveData(){
    localStorage.setItem("data",listContainer.innerHTML);
}
function showList(){
    listContainer.innerHTML=localStorage.getItem("data");
}
showTask();