使用 vanilla JavaScript 根据索引移动元素

Question

我想根据索引移动我的元素（待办事项列表中的任务）。如果指数增加，则div向下移动；如果下降，则div上升。我了解的功能insertBefore和insertAfter，但不幸的是，我不知道如何使用它们。var task = [];function newElement(newChild) {    let btnDel = document.createElement("button");    btnDel.className = "fa fa-trash-o";    let myEd = document.getElementById("myEdit");    let spanClose1 = document.getElementsByClassName("close1")[0];    let spanRedact = document.getElementsByClassName("redact")[0];    let myDel = document.getElementById("myDelete");    let spanClose = document.getElementsByClassName("close")[0];    let spanYes = document.getElementsByClassName("yes")[0];    // Create button    let divWithBut = document.createElement("div");    divWithBut.className = "forButt";    let btnRedact = document.createElement("button");    btnRedact.className = "fa fa-pencil";    // Redact but    btnRedact.onclick = function() {        myEd.style.display = "block";        let editText = document.getElementById("editText");        let divWithText = divWithBut.parentElement.getElementsByClassName("todoPost")[0];        editText.value = divWithText.innerHTML;        editText.currentTarget;        spanRedact.onclick = function() {            divWithText.textContent = editText.value;            divWithText.className = "todoPost";            myEd.style.display = "none";        };        spanClose1.onclick = function() {            myEd.style.display = "none";        };    }    /*************************** */    /* Done but */    let doneBut = document.createElement("button");    doneBut.className = "fa fa-check-circle-o";    doneBut.onclick = function() {        let divWithText = divWithBut.parentElement.getElementsByClassName("todoPost")[0];        divWithText.classList.toggle("checked");    }