<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <div id="box"> <div>111</div> </div> <script> =the p-varcreate a DOM object in memory// document.createElement ( ' p ' ); // set the object attribute p.innerText = ' Hello ' ; p.style.color = ' Red ' ; // the p element, into DOM tree var Box = document.getElementById ( ' Box ' ); box.appendChild (P); </ Script > </ body > </ HTML >