如何使用JavaScript删除HTML中的子节点？

var parentElement = document.getElementById("parent");
var childElement = document.getElementById("child");
parentElement.removeChild(childElement);

var parentElement = document.getElementById("parent");
parentElement.innerHTML = "";

var childElement = document.getElementById("child");
childElement.remove();

var parentElement = document.getElementById("parent");
while (parentElement.childNodes.length > 0) {
  parentElement.childNodes[0].remove();
}