document.getElementById is returning null or undefined everytime
Question
Javascript code is
function addConformationNo(){
var confirmationNo = document.getElementById("addedconfirmation").val();
alert(confirmationNo);
}
and I'm calling addConformationNo() function on click of a button
When the addConformationNo() function is executed, the function call to document.getElementById returns null everytime. Why? Any clues?
3 answers
solution1
5 2014-05-09 12:20:02
Either:
- You don't have an element of that id
- You are calling the function before the element exists
- You are misreading the error message
DOM elements do not have val methods associated with them, so you are likely to get a "Property is undefined or not a function" error, but that is complaining about val not the return value of getElementById .
Access the value property instead.
var confirmationNo = document.getElementById("addedconfirmation").value;
solution2
0 2014-05-09 12:21:22
var confirmationNo = document.getElementById("addedconfirmation").value;
will do.
You can also inspect element by right clicking on the browser or you can check the javascript console in your browser.
<html>
<head>
<script type=text/javascript>
function addConformationNo(){
var confirmationNo = document.getElementById("addedconfirmation").value;
alert(confirmationNo);
}
</script>
</head>
<body>
<input type = "text" name = "addedconfirmation" id = "addedconfirmation" />
<input type="submit" onclick="addConformationNo();">
</body>
</html>
solution3
0 2020-08-06 10:59:55
If you are getting such a message for every element. Then you may have included the javascript file at the beginning of HTML on the top instead of the bottom.
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