Need to escape a special character in a jQuery selector string

CSS character escape sequences (as used in selectors) are tricky. They’re so tricky I even made a web app that can tell you how to escape any character in CSS.

It’s much simpler and more efficient to simply select all option elements and then filter them based on their value attribute value:

var value = this.value;
$select.find('option').filter(function() {
  return this.value == value;
}).show();

That way, no special escaping is needed at all.

Late to answer but,

jQuery 3

and adding missing "" in 'option[value="'+ val +'"]'

var val = "something[4][2]";

$("select").find('option[value="' +  val  + '"]').show();

option{
  display: none;
}

<script src="https://code.jquery.com/jquery-3.1.0.js"></script>

<select>
  <option value="something[4][2]">4,2</option>
  <option value="something[1][1]">1,1</option>
</select>

jQuery 3 and jQuery.escapeSelector()

without wrapping quotes - so using your original selector 'option[value='+ val +']'

var val = "something[4][2]";           
var eSel = $.escapeSelector( val );    // something\[4\]\[2\]

$("select").find('option[value='+ eSel +']').show();

option{
  display: none;
}

<script src="https://code.jquery.com/jquery-3.1.0.js"></script>

<select>
  <option value="something[4][2]">4,2</option>
  <option value="something[1][1]">1,1</option>
</select>

Put quotes around the attribute value in the selector, then you only have to escape backslashes and quotes in the value:

var val = $(this).attr('val');

val = val.replace(/\\/g, "\\\\").replace(/"/g, '\\"');

$select.find('option[value="' +  val + '"]').show();

If you know that the value doesn't have any backslashes or quotes (like in your example), then you don't need to escape anything in the value, you only need the quotes in the selector.

If the selector ends with the special char, you can't escape it using double backslashes. The work arround is to use regex : For example, if the selector id is "bonus+" then you can use:

$("div[id$='bonus+']")

It makes more sense when you have dynamic selectors.

If you want something that works with any sort of value, try this:

var val = $(this).attr('val').replace(/[!"#$%&'()*+,.\/:;<=>[email protected][\\\]^`{|}~]/g, "\\\\$&")

This works by escaping all CSS meta-characters listed on the Selectors page of the jQuery documentation with two backslashes.

Keep in mind that in your situation, there is no need to do something tricky like this. You can use the filter function to select all option elements with a given value without having to escape the value, as described in Mathias Bynens's answer.

Check this out...

var val = $(this).attr('val').replace(/(\[|\])/g, '\\\\$1'); // something\\[4\\]\\[2\\]

of course, this only handles the brackets, not any other of the special characters. However, in my experience, the brackets are the only ones I use (because of PHP's handy way of handling input name attributes like these: something[])

jQuery's FAQ has a nice solution for this that escapes all character that jQuery requires.

I like this nullsafe version of what they suggest:

function jqid (id) {
  return (!id) ? null : '#' + id.replace(/(:|\.|\[|\]|,|=|@)/g, '\\$1');
}