Question

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jQuery: Checking if next element exists

I’m implementing a custom slider using jquery. There I want to give facility to load next/previous image when user press right/left keys respectively.

It is working fine but when cursor reach last/first element, code breaks as it do not find further elements. My code is as follow:

function movePointer(dir){
    var selected = $("#imgslider > ul > li > img.siddslideselected");
    console.log(selected);
    var selectedli = selected.parent();
    if(dir=='left'){
        var nabourele = selectedli.prev()
    }else if(dir=='right'){
        var nabourele = selectedli.next();
    }
    console.log(nabourele);
    if(nabourele){
        selected.removeClass('siddslideselected');
        nabourele.children().addClass('siddslideselected').trigger('click');
    }
}

If current position of cursor is in middle, everything work fine but if cursor is on first element, pressing left key breaks the code. I try to stop that by checking if(nabourele){, but it is not working. console log for nabourele show [] in that case.

How can I test condition if next/prev element exist or not?

Answer 1

You have to test the length property:

if ( nabourele.length )