Why does this javascript code prints the first list entry only ?

Question

0.00/5 (No votes)

See more:

I am a beginner in javascript. I was trying to write a code that takes input from the user in textboxes . I wanted to capture the inputs in an array, so i looked up for a method on the internet. I got a method document.getElementsByName("name") that returns an HTML collection of all element with that name. I wrote a script to utilise that function, but strangely, it is just printing only the first value in the list. The length function shows me the correct length, i.e 3 , but only the first value is being printed. Any help would be appreciated. Here is the code:

<html>
<head>
<title>Test</title>
<script type="text/javascript">
function fun(){
		var list = document.getElementsByName("array");
		document.write(list[0].value+"<br>");
		document.write(list[1].value+"<br>");
		document.write(list[2].value+"<br>");
		
}
</script>
</head>
<body>
<input type="text" name="array"><br>
<input type="text" name="array"><br>
<input type="text" name="array"><br>
<input type="button" value="go" onclick="fun()">
</body>
</html>

What I have tried:

I have tried printing the length, as well as individual elements of the list one by one. All of them works. But when i want to print all of the values at once, it just prints the first value

Posted 4-Aug-17 5:55am

AbhayPrakash

Updated 4-Aug-17 6:12am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Answer 1 · 2017-08-04T06:08:00

Check out the error console in your browser, and you'll see the problem:

TypeError: list[1] is undefined

As soon as you use document.write, the entire contents of the document are replaced with whatever you've written.

Document.write() - Web APIs | MDN[^]:
Note: as document.write writes to the document stream, calling document.write on a closed (loaded) document automatically calls document.open, which will clear the document.

Clearing the document destroys the elements on it, so you can no longer read the value of the inputs.

You'll need to read the values before writing to the document:

JavaScript

function fun(){
    var list = document.getElementsByName("array");
    
    var values = [];
    for (var i = 0; i < list.length; i++){
        values.push(list[i].value);
    }
    
    document.write(values.join("<br />"));
    document.close();
}

Jameel VM · Answer 2 · 2017-08-04T06:12:00

Solution 2

Here is the working Plunker. When you use document.write , it will overwrite the previous value.

Working Plunker[^]

Hepe this helps

Posted 4-Aug-17 6:12am

Jameel VM