1）内部网页

设置标记内的所有HTML内容 返回标记内的所有HTML内容 包括样式+空白

2) innerText

设置标记内的所有内容(使用标记对应的换行符) 返回标签内的所有HTML内容(带有标签对应的换行符) 忽略标签(只显示文本) 忽略样式+空白 如果我们有style:"visibility:hidden;"内标签 |_ innerText包含样式->隐藏内容

(3) textContent

设置标签内的所有内容(没有标签对应的换行符) 返回标签内的所有内容(没有标签对应的换行符) 包括空格 如果我们有style:"visibility:hidden;"内标签 |_ textContent忽略样式->显示内容 textContent具有更好的性能，因为它的值不会解析为HTML。

@rule:

innerHTML

write:写入ele的任何字符串。innerHTML, ele (html文件中元素的代码)将与它在String中所写的完全相同。 阅读:你从ele中读到的任何东西。innerHTML到一个字符串，字符串将完全相同，它是在ele (html文件)。

=> .innerHTML将不会为您的读/写做任何修改

innerText

write: when you write a String to the ele.innerText, any html reserved special character in the String will be encoded into html format first, then stored into the ele. eg: <p> in your String will become &lt;p&gt; in the ele read : when you read from the ele.innerText to a String, any html reserved special character in the ele will be decoded back into a readable text format, eg: &lt;p&gt; in the ele will become back into <p> in your String any (valid) html tag in the ele will be removed -- so it becomes "plain text" eg: if <em>you</em> can in the ele will become if you can in your String about invalid html tag if there is an invalid html tag originally in the ele (the html code), and you read from.innerText, how does the tag gets removed? -- this ("if there is an invalid html tag originally") should not (is not possible to) happen but its possible that you write an invalid html tag by .innerHTML (in raw) into ele -- then, this may be auto fixed by the browser. dont take (-interpret) this as step [1.] [2.] with an order -- no, take it as step [1.] [2.] are executed at the same time -- I mean, if the decoded characters in [1.] will form a new tag after the conversion, [2.] does not remove it (-- cuz [2.] considers what characters are in the ele during the conversion, not the characters they become into after the conversion) then stored into the String.

有解释

(^在js文件的注释中包含了更多的解释，+在console.log中输出 下面是一个简化的视图，带有一些输出。 (自己尝试代码，也不能保证我的解释是100%正确的。))

<p id="mainContent">This is a <strong>sample</strong> sentennce for Reading.</p>
<p id="htmlWrite"></p>
<p id="textWrite"></p>

// > @basic (simple)
// read
var ele_mainContent = document.getElementById('mainContent');
alert(ele_mainContent.innerHTML); // This is a <strong>sample</strong> sentennce for Reading.        // >" + => `.innerHTML` will **not make any modification** for your read/write
alert(ele_mainContent.innerText); // This is a sample sentennce for Reading.                         // >" 2. any (valid) `html tag` in the `ele` will be **removed** -- so it becomes "plain text"

// write
var str_WriteOutput = "Write <strong>this</strong> sentence to the output.";
var ele_htmlWrite = document.getElementById('htmlWrite');
var ele_textWrite = document.getElementById('textWrite');
ele_htmlWrite.innerHTML = str_WriteOutput;
ele_textWrite.innerText = str_WriteOutput;

alert(ele_htmlWrite.innerHTML); // Write <strong>this</strong> sentence to the output.               // >" + => `.innerHTML` will **not make any modification** for your read/write
alert(ele_htmlWrite.innerText); // Write this sentence to the output.                                // >" 2. any (valid) `html tag` in the `ele` will be **removed** -- so it becomes "plain text"                     
alert(ele_textWrite.innerHTML); // Write &lt;strong&gt;this&lt;/strong&gt; sentence to the output.   // >" any `html reserved special character` in the String will be **encoded** into html format first               
alert(ele_textWrite.innerText); // Write <strong>this</strong> sentence to the output.               // >" 1. any `html reserved special character` in the `ele` will be **decoded** back into a readable text format,  

// > @basic (more)
// write - with html encoded char
var str_WriteOutput_encodedChar = "What if you have &lt;strong&gt;encoded&lt;/strong&gt; char in <strong>the</strong> sentence?";
var ele_htmlWrite_encodedChar = document.getElementById('htmlWrite_encodedChar');
var ele_textWrite_encodedChar = document.getElementById('textWrite_encodedChar');
ele_htmlWrite_encodedChar.innerHTML = str_WriteOutput_encodedChar;
ele_textWrite_encodedChar.innerText = str_WriteOutput_encodedChar;

alert(ele_htmlWrite_encodedChar.innerHTML); // What if you have &lt;strong&gt;encoded&lt;/strong&gt; char in <strong>the</strong> sentence?
alert(ele_htmlWrite_encodedChar.innerText); // What if you have <strong>encoded</strong> char in the sentence?
alert(ele_textWrite_encodedChar.innerHTML); // What if you have &amp;lt;strong&amp;gt;encoded&amp;lt;/strong&amp;gt; char in &lt;strong&gt;the&lt;/strong&gt; sentence?
alert(ele_textWrite_encodedChar.innerText); // What if you have &lt;strong&gt;encoded&lt;/strong&gt; char in <strong>the</strong> sentence?


// > @note-advance: read then write 
var ele__htmlRead_Then_htmlWrite = document.getElementById('htmlRead_Then_htmlWrite');
var ele__htmlRead_Then_textWrite = document.getElementById('htmlRead_Then_textWrite');
var ele__textRead_Then_htmlWrite = document.getElementById('textRead_Then_htmlWrite');
var ele__textRead_Then_textWrite = document.getElementById('textRead_Then_textWrite');

ele__htmlRead_Then_htmlWrite.innerHTML = ele_mainContent.innerHTML;
ele__htmlRead_Then_textWrite.innerText = ele_mainContent.innerHTML;
ele__textRead_Then_htmlWrite.innerHTML = ele_mainContent.innerText;
ele__textRead_Then_textWrite.innerText = ele_mainContent.innerText;

alert(ele__htmlRead_Then_htmlWrite.innerHTML); // This is a <strong>sample</strong> sentennce for Reading.
alert(ele__htmlRead_Then_htmlWrite.innerText); // This is a sample sentennce for Reading.
alert(ele__htmlRead_Then_textWrite.innerHTML); // This is a &lt;strong&gt;sample&lt;/strong&gt; sentennce for Reading.
alert(ele__htmlRead_Then_textWrite.innerText); // This is a <strong>sample</strong> sentennce for Reading.
alert(ele__textRead_Then_htmlWrite.innerHTML); // This is a sample sentennce for Reading.
alert(ele__textRead_Then_htmlWrite.innerText); // This is a sample sentennce for Reading.
alert(ele__textRead_Then_textWrite.innerHTML); // This is a sample sentennce for Reading.
alert(ele__textRead_Then_textWrite.innerText); // This is a sample sentennce for Reading.


// the parsed html after js is executed
/*
<html><head>
<meta charset="utf-8">
<title>Test</title>
</head>
<body>
<p id="mainContent">This is a <strong>sample</strong> sentennce for Reading.</p>
<p id="htmlWrite">Write <strong>this</strong> sentence to the output.</p>
<p id="textWrite">Write &lt;strong&gt;this&lt;/strong&gt; sentence to the output.</p>
<!-- P2 -->
<p id="htmlWrite_encodedChar">What if you have &lt;strong&gt;encoded&lt;/strong&gt; char in <strong>the</strong> sentence?</p>
<p id="textWrite_encodedChar">What if you have &amp;lt;strong&amp;gt;encoded&amp;lt;/strong&amp;gt; char in &lt;strong&gt;the&lt;/strong&gt; sentence?</p>
<!-- P3 @note: -->
<p id="htmlRead_Then_htmlWrite">This is a <strong>sample</strong> sentennce for Reading.</p>
<p id="htmlRead_Then_textWrite">This is a &lt;strong&gt;sample&lt;/strong&gt; sentennce for Reading.</p>
<p id="textRead_Then_htmlWrite">This is a sample sentennce for Reading.</p>
<p id="textRead_Then_textWrite">This is a sample sentennce for Reading.</p>

</body></html>
*/

var element = document.getElementById("main");
var values = element.childNodes[1].innerText;
alert('the value is:' + values);

要进一步细化它并检索值Alec(例如，使用另一个.childNodes[1])

var element = document.getElementById("main");
var values = element.childNodes[1].childNodes[1].innerText;
alert('the value is:' + values);

InnerText将仅以纯文本形式返回页面的文本值，其中每个元素在换行符上，而innerHTML将返回body标记内所有内容的HTML内容，而childNodes将返回一个节点列表，顾名思义。

就mutation观察者而言，设置innerHTML会生成一个childList突变，因为浏览器会删除节点，然后添加一个带有innerHTML值的新节点。

如果设置innerText，则会生成characterData突变。

简单地说:

innerText将显示值，并忽略任何HTML格式可能 被包括。 innerHTML将显示值并应用任何HTML格式。