Get the selected item in a drop down dynamically

Actually I forgot to add this topic. I think this is the topic to discuss first. Anyway this post will tell you how to get the selected item, the selected value in a set of options of a select input field of an HTML form. The value is accessed or retrieved using java script or jquery API. The code is below.

java script code : 

document.getElementById("SELECT_ID").value;

jquery code :

$("#SELECT_ID").val();

For eg:-

If the HTML code is as below then the code will be as explained below,

<select name="sel_name" id="sel_id">

<option value="I will help you">I will help you</option>

<option value="I will not help you">I will not help you</option>

<option value="I can assist you">I can assist you</option>

<option value="I cant assist you">I cant assist you</option>

</select>

Then the java script code to dynamically pick the selected option is,

document.getElementById("sel_id").value;

and the jquery code for the same is,

$("#sel_id").val();

Add Drop down or list dynamically into an HTML form

In the previous articles we have discussed about how to different dynamic actions related to a select input field in an HTML form, in whatever form or name it is, i.e. the same is called a drop down list or list box or combo box. Now in this article I want tell you how to insert a select field dynamically to an HTML form. This too using the same java script or jquery APIs. Sure you can do the previous experiments of inserting options or deleting it or counting or set a new value as selected all using the same code discussed in previous articles. So let us do it, add a drop down to a form.

The javascript code to achieve this task is,

var my_form = document.getElementById('id_form');

var my_select = document.createElement('select');

my_select.setAttribute('id','id_select');

my_form.appendChild(my_select);

Note:-
1. Replace the 'id_form' with the id of the form to which you want to insert the select element

2.Replace the 'id_select' with the id you want to use for the newly added select box.

The same using jquery,

$("#id_form").append('<select id="id_select"></select>');

For eg:-

If the HTML code is as below then the javascript and jquery code following it can be used to do the same,

<form id="test_form">
<input type="text" name="name" value="test" >
</form>

javascript code,

var my_form = document.getElementById('test_form');

var my_select = document.createElement('select');

my_select.setAttribute('id','test_select');

my_form.appendChild(my_select);

jquery code:

$("#test_form").append('<select id="test_select"></select>');

If you want mix the jquery APIs and the javascript (the core java script I mean, jquery too is javascript itself, but a framework made of javascript), the same can be accomplished using the snippet,

var my_select = document.createElement('select');

my_select.setAttribute('id','test_select');

$("#test_form").append(my_select);

Hopes you enjoyed this code, if you need any more explanation or clarification feel free to put your comments.

Remove an option dynamically from Drop down or list using javascript and jquery

If there is a requirement to delete an existing option from a select input field in a form dynamically,  that can be a list box or combo, i.e drop down type of select. You can dynamically remove an option from it using java script or jquery using the following code snippet. The id selector is used here, if you wish you can use other selectors also. To remove an option from select, the following java script can be used,

document.getElementById('SELECT_ID').remove(option_index);

the same can be achieved using the following jquery snippet,

$("#SELECT_ID option[value='OPTION_VALUE']").remove();

For eg:- if the html code for the select is like this,

<select id='myselect'>
<option value="I loves Linux">I loves Linux</option>
<option value="I use windows too">I use windows too</option>
<option value="Linux is free software">Linux is free software</option>
<option value="Java script is simple">Java script is simple</option>
</select>

then the java script code to remove the option 'I use windows too' will be,

document.getElementById('myselect').remove(1); //it is 1 because the index start from 0

using jquery,

$("#myselect option[value='I use windows too']").remove();

Setting value of drop down dynamically using javascript or jquery

If you want dynamically select or set a select or drop down or list box input value, in such cases the javascript or jquery code can be used to do this. Just a single line of code can do this as shown below. You will need to specify the unique id of the input field. You can use other jquery selectors too to do this if you don't want use the id.

To set the value of a select (drop down or list box) using java script is like this,

document.getElementById('Drop_Down_ID').value='The Option to Set';

the same can be achieved using jquery using this,

$("#my_select").val("The Option to Set");

for e.g:- if our html is like this,

<select id="my_select">

<option value="Want start a business">Want start a business</option>

<option value="Want find a job">Want find a job</option>

<option value="Want marry">Want marry</option>

<option value="Want sleep">Want sleep</option>

</select>

then we can use the javascript code as,

document.getElementById('my_select').value='Want marry';

to set the same option using jquery is,

$("#my_select").val("Want marry");