Getting the selected option in Javascript/Node.js

Question

Self teaching Node.js and Javascript stuff. I have in the form in my HTML and select, drop down menu option. How do I get the index of the selected value?

So far im trying this:

var e = req.body.boolean_choice;
boolChoice = e.selectedIndex;

I have the req.body working for getting the inputted values in a text box, but it tells me selectedIndex is not a thing. So then I tried:

var e = req.body.boolean_choice

to see what that gave and it just gave undefined.

Is there a way to do this?

Here is the HTML:

<form action="http://localhost:3000" method="POST">
Form:<br>
<br>
<br>
Text Box 1: <input type="text" name="tb1"  size="35" placeholder="&quot;@10SadioMane&quot; OR &quot;#Mane&quot;">
<br>
<br>
<select id="choice" name="choice">
  <option value="OR">OR</option>
  <option value="AND">AND</option>
</select>
<br>
<br>
<input type="submit" value="Submit">

Use selection option value as an array of object with index and value like [{"id":1, "name":"test"}, ... ], and in select function call send the id rather than name. — mohan rathour, May 05 '17 at 12:51
maybe this old question can help: [http://stackoverflow.com/questions/1085801/get-selected-value-in-dropdown-list-using-javascript](http://stackoverflow.com/questions/1085801/get-selected-value-in-dropdown-list-using-javascript) — user1799565, May 05 '17 at 12:52
@DominicReeve your select name is *choice*, not *boolean_choice* — Serge K., May 05 '17 at 13:01
@NathanP. Thank you so much! I can't believe I had missed that! Thanks — Dominic Reeve, May 05 '17 at 13:03

score 3 · Answer 1 · answered May 05 '17 at 12:51

3

Form submitting will pass only value property of selection. Also use debugger in IDE that you use, to explore req.body, instead of trying to guess what's there.

answered May 05 '17 at 12:51

Sergey Yarotskiy

4,536
2
19
27

1

or do `console.log(req.body)` to view it in the console running node – George May 05 '17 at 12:53
im not guessing at what is there, I've used `req.body.tb1` which returns the input of that text box. So I assumed the logic would be the same for this. – Dominic Reeve May 05 '17 at 12:59

Swastik Pareek · Answer 2 · 2017-05-05T13:04:27.503

0

Happy to help.

First of all get the Selected option DOM element

var el = document.querySelector('#choice option:selected');

ibn your case it will be req.body.querySelector('#choice option:selected');

Now logic is to iterate to the previous siblings in the chain till you reach to the top.

var index = 0; 
while( el.previousSibling ! == null){
el = el.previousSibling;
index +=1;
}
console.log(index);

edited May 05 '17 at 13:04

answered May 05 '17 at 12:55

Swastik Pareek

161
1
8

Since he using `req.body` I suppose he need index on server side. – Sergey Yarotskiy May 05 '17 at 13:01
`option:selected` is not a valid selector, valid for jQuery – AamirR Aug 05 '22 at 07:10

Getting the selected option in Javascript/Node.js

2 Answers2