将值设置为getElementsByName的数组

Question

I am having the following situation:

I must use dynamic table (add/remove rows) - code from http://viralpatel.net/blogs/dynamically-add-remove-rows-in-html-table-using-javascript/

rows contain html input boxes with name, no id

I need to be able to set values to these boxes

I have tried the following, but get into syntax problem:

<!-- html part -> this row will be replicated by the dynamic table code -->

 <tr><td><input type=input name=mybox></td></tr> //js part - variant 1: document.getElementsByName("mybox").item(j).value = j; //js part - variant 2: document.getElementsByName("mybox")[j].setAttribute("value", j); 

None of these seems to work. Can you suggest a right way to do it?

Thanks!

Answer 1

getElementsByName returns an array of HTMLElements.

This line has the correct syntax but I doubt j , the value you are trying to set is the right index value of the returned array.

document.getElementsByName("mybox")[j].setAttribute("value", j);

The fist occurrence of j should be the index of the returned array. If It's the first element found by the given name then 0, if the 2nd, then 1, etc.

Answer 2

document.getElementsByName("mybox")[j].value = j;

Answer 3

您的html代码似乎有误，请尝试使用双引号：

<tr><td><input type="input" name="mybox"></td></tr>

Answer 4

We don't know what is the value of j and how it's being set.

First variant should work. Just set a value that makes sense. For testing purposes: document.getElementsByName("mybox")[3].value = "Test";

Also use quotes for attributes type="input" and name="mybox"

Answer 5

试试这个$("#mybox").eq(j).val("your value");

Answer 6

thank you for the feedback.

Michal's solution is the one I got working.

document.getElementsByName("mybox")[3].value = "Test";

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

However I tried my 2nd variant as suggested by Marcell Fülöp in a very rudimentary way and saw some strange behaviour:

//manual assignment of indexes
document.getElementsByName("mybox")[0].setAttribute("value",0);
document.getElementsByName("mybox")[1].setAttribute("value",1);
document.getElementsByName("mybox")[2].setAttribute("value",2);

The strange result was only the 1st box got it's value. I'd be happy to understand why...