分割文本节点

 1 var element = document.createElement("div");
 2 element.className = "message";
 3 
 4 var textNode = document.createTextNode("Hello world!");
 5 element.appendChild(textNode);
 6 
 7 document.body.appendChild(element);
 8 
 9 var newNode = element.firstChild.splitText(5);
10 console.log(element.firstChild.nodeValue);
11 console.log(newNode.nodeValue);
12 console.log(element.childNodes.length);