How select the previous option with jQuery?

user_8195985 0
Viewed 1130

I have a html page with a select element like this:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
<select id="ExSelect">
  <option>1</option>
  <option>2</option>
  <option>3</option>
  <option>4</option>
  <option>5</option>
  <option>6</option>
  <option>7</option>
  <option>8</option>
  <option>9</option>
  <option>10</option>
 </select>
  <br>
  <br>
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
  <button onclick="ToTheNext()" id="btnext">Next</button>
</body>
</html>

And I'm using this simple function on the button OnClick to change the selected item to the next option item of the dropdown:

function ToTheNext()
{
    $('#ExSelect option:selected').next().attr('selected', 'selected');
}

My question is: How can i change the selected item to the previous option of this tag using Vanilla JavaScript or jQuery?

Jsbin Example: https://jsbin.com/nuyeduf/edit?html,js,output

html jquery javascript
4 Answers

Two problems - first by using attr you're setting more than one option to selected, which is probably not what you want to do as it will stop the prev() from working as you expect.

Change your code like this:

function ToTheNext()
{
    $('#ExSelect option:selected').next().prop('selected', true);
}

function ToThePrevious()
{
    $('#ExSelect option:selected').prev().prop('selected', true);
}

https://jsbin.com/xewopobasi/1/edit?html,js,output

If you're using jQuery then stop using onclick attributes and instead assign click handlers appropriately

$('#btnext').on('click', function(){
    $('#ExSelect option:selected').next().prop('selected', true);
});


$(function(){

  $('#btnext').on('click',function(){
    $('#ExSelect option:selected').next().prop('selected', true);
  });

  $('#btprev').on('click',function(){
    $('#ExSelect option:selected').prev().prop('selected', true);
  });

});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="ExSelect">
  <option>1</option>
  <option>2</option>
  <option>3</option>
  <option>4</option>
  <option>5</option>
  <option>6</option>
  <option>7</option>
  <option>8</option>
  <option>9</option>
  <option>10</option>
 </select>
  <br>
  <br>
  <button id="btnext">Next</button>
  <button id="btprev">Prev</button>

user_2196610

Replace the .attr('selected', 'selected'); with .prop('selected', true);

next() with prev()

and add the jQuery script under the button.

const select = $('#ExSelect');

function next()
{
   select.find('option:selected').next().prop('selected', true);
}

function prev()
{
  select.find('option:selected').prev().prop('selected', true);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="ExSelect">
  <option>1</option>
  <option>2</option>
  <option>3</option>
  <option>4</option>
  <option>5</option>
  <option>6</option>
  <option>7</option>
  <option>8</option>
  <option>9</option>
  <option>10</option>
</select>
<button onclick="next()" id="btnext">Next</button>
<button onclick="prev()" id="btprev">Prev</button>

user_54969730

Use $('#ExSelect option:selected').prev().prop('selected', true);

user_86958280

In order to complete the answer. If you want to trigger something with the new selected option, you must add .change() at the end of your functions :

function ToTheNext(){
    $('#ExSelectoption:selected').next().prop('selected', true).change();
}

function ToThePrevious(){
    $('#ExSelectoption:selected').prev().prop('selected', true).change();
}
user_138301350
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