<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div id="i1">观沧海
<a href="#">
<span>观沧海</span></a>
</div>
<input type="text" id="i2">
<input type="password" id="i3">
<select id="i4">
<option value="11">东陵碣石</option>
<option value="12">以观沧海</option>
<option value="13">树木丛生</option>
</select>
<textarea id="i5"></textarea>
</body>
</html>
console调试记录：
var obj = document.getElementById('i1');
undefined
obj.innerText
"观沧海 观沧海"
obj.innerHTML
"观沧海
<a href="#">
<span>观沧海</span></a>
"
obj.innerText='<a href='#'>sadasd</a>'
obj.innerText="<a href='#'>sadasd</a>"
"<a href='#'>sadasd</a>"
obj.innerHTML="<a href='#'>sadasd</a>"
"<a href='#'>sadasd</a>"
var obj = document.getElementById('i2');
undefined
obj.value
""
obj.value
"asdasd"
obj.value=23123
23123
var obj = document.getElementById('i3');
undefined
obj.value
"123123123"
obj.value=444444
444444
obj.value
"444444"
var obj = document.getElementById('i4');
undefined
obj.value
"11"
obj.value
"13"
obj.value=12
12
var obj = document.getElementById('i5');
undefined
obj.value
""
obj.value
"asdddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"