javascript 如何循环遍历 html 中的 ID 元素
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How to loop through ID elements in html
提问by Niall_Maher
I'm trying to loop through all ID fields in my html and print them to a text field using JavaScript.
This is what I have:
Thanks for you help :-)
** It looks like most of your question is code, please give more details**
我正在尝试遍历 html 中的所有 ID 字段，并使用 JavaScript 将它们打印到文本字段。这就是我所拥有的：感谢您的帮助 :-)
** 看起来您的大部分问题都是代码，请提供更多详细信息**
<html>
<head>
<title>Modifying Sentiment</title>
</head>
<body>
<body bgcolor="#E6E6FA">
<font color=black size=+3>Modifying Sentiment</font>
<table>
<tr><td>Text to Save:</td></tr>
<tr>
<td colspan="3">
Add positive adjective:
<img Adjective src="http://findicons.com/files/icons/2776/android_icons/96/ic_question_mark.png" alt="question" title="Adjective: is a word naming an attribute of a noun, such as sweet, red, or technical."
width=20 />
<br>
<textarea cols=40 rows=3 id="textBox1" ></textarea>
<p>
<textarea id="textBox2" style="width:512px;height:256px"></textarea>
</td>
</tr>
<tr>
<td>Filename to Save As:</td>
<td><input id="inputFileNameToSaveAs"></input></td>
<td><button onclick="saveTextAsFile()">Save Text to File</button></td>
</tr>
<tr>
<td>Select a File to Load:</td>
<td><input type="file" id="fileToLoad"></td>
<td><button onclick="loadFileAsText()">Load Selected File</button><td>
</tr>
</table>
<script type='text/javascript'>
function saveTextAsFile()
{
var el;
var prefix = 'textBox';
for(var i = 0; el = document.getElementById(prefix + i); i++){
if (el != ""){
var textToWrite = document.getElementById("el").value;
var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
var fileNameToSaveAs = document.getElementById("inputFileNameToSaveAs").value;
}
}
var downloadLink = document.createElement("a");
downloadLink.download = fileNameToSaveAs;
downloadLink.innerHTML = "Download File";
if (window.webkitURL != null)
{
downloadLink.href = window.webkitURL.createObjectURL(textFileAsBlob);
}
else
{
downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
downloadLink.onclick = destroyClickedElement;
downloadLink.style.display = "none";
document.body.appendChild(downloadLink);
}
downloadLink.click();
}
function destroyClickedElement(event)
{
document.body.removeChild(event.target);
}
function loadFileAsText()
{
var fileToLoad = document.getElementById("fileToLoad").files[0];
var fileReader = new FileReader();
fileReader.onload = function(fileLoadedEvent)
{
var textFromFileLoaded = fileLoadedEvent.target.result;
document.getElementById("inputTextToSave").value = textFromFileLoaded;
};
fileReader.readAsText(fileToLoad, "UTF-8");
}
</script>
<input type=reset value=Clear id="reset">
</body>
</html>
回答by joyBlanks
You can select all the elements as document.querySelectorAll('[id^=textbox]')
您可以选择所有元素作为 document.querySelectorAll('[id^=textbox]')
Iterate it over the NodeList that the above query returns.
在上述查询返回的 NodeList 上迭代它。
Code
代码
var textBoxes = document.querySelectorAll('[id^=textbox]');
var textToWrite;
for(var i in textBoxes){
textToWrite = textBoxes[i].value;
/* do your thing */
}
