TypeError:document.getElementbyId不是函数

Question

在下面的代码片段中,一切都按预期工作,但当我点击"显示源代码"时,Firefox会产生此错误:

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[11:07:30.630] TypeError: document.getElementbyId is not a function @ http://localhost:8888/html5/native-rich-text.html:10

Safari也会产生类似的错误.是什么造成的？

function showSource() {
  var content = document.getElementbyId("edit").innerHTML
  content.replace(/</g, '&lt;');
  content.replace(/>/, '&gt: ');
  prompt("Your Code:", content);

}

function createLink() {
  var url = prompt("Enter URL:", "http://");
  if (url)
    document.execCommand("createlink", false, url);
}

<h1>Native Rich Text</h1>
<p>No textboxes here, that's a &lt;div&gt; element!</p>
<div>
  <input type="button" value="Bold" onclick="document.execCommand('bold', false, null);">
  <input type="button" value="Italic" onclick="document.execCommand('italic', false, null);">
  <input type="button" value="Underline" onclick="document.execCommand('underline', false, null);">
  <input type="button" value="Add Link" onclick="createLink();">
  <input type="button" value="Show Source" onclick="showSource();">
</div>
<div id="edit" style="border:solid black; height: 300px; width: 400px;" contenteditable="true">
  Hello!
</div>

Answer 1

区分大小写:( document.getElementById注意资本B).

Answer 2

JavaScript区分大小写.该b中getElementbyId应大写.

var content = document.getElementById("edit").innerHTML;