Question

I have the below code which works fine.

    <div id="testdiv"></div>
    <table>
        <tr>
            <td class="test" title="two">2</td>
            <td class="test" title="one">1</td>
            <td class="test" title="three">3</td>
        </tr>
    </table>

    <script>
        if(jQuery("td[title='three']").length == 0) {
          jQuery('#testdiv').append('<p>no td</p>')
        }
        else
        {
          jQuery('#testdiv').append('<p>yes td</p>')
        }
    </script>

However I want to say if either title one or three are present. So I tried editing the first line of my script to look like this.

if(jQuery("td[title='three']").length == 0 || jQuery("td[title='one']").length == 0) {

But for some reason it seems as though both three and one need to be there for my statement to be true?

But if I replace the || with the && it works how I want it to? Why is it that the && is working like an || here or am I missing something here?

See fiddle for example

Answer 1

|| is OR, && is AND so if you need both conditions to be met you have to use &&, but you can make this a bit shorter. I’m using $ for convenience but you can replace with jQuery:

var exists = $('td[title=one],td[title=three]').length;
$('#testdiv').append('<p>'+ (exists ? 'yes' : 'no') +' td</p>');