如何在父div上创建div行？

<div id="parentDiv"></div>

// 获取父div元素
var parentDiv = document.getElementById("parentDiv");

// 创建子div元素
var childDiv1 = document.createElement("div");
var childDiv2 = document.createElement("div");

// 设置子div的样式
childDiv1.style.width = "100%";
childDiv1.style.height = "50px";
childDiv1.style.backgroundColor = "red";

childDiv2.style.width = "100%";
childDiv2.style.height = "50px";
childDiv2.style.backgroundColor = "blue";

// 将子div添加到父div中
parentDiv.appendChild(childDiv1);
parentDiv.appendChild(childDiv2);