jQuery: Checking if next element exists

Use the length method in jQuery:

if($(...).next().length > 0) {
    alert("Exists.")
} else {
    alert("Doesn't exist!")
}

The briefest method is just:

if( $( ... ).next('li')[0] ) {

Since jQuery functions always return a jQuery object, it's never equal to null. But accessing a jQuery object like an array acts like you are using an array of DOM objects, so [0] will pull the first matched DOM element or null. Checking .length() against 0 works, as well.

Have you tried looking at .next('li').length?

Use jQuery .is(), using .is() you can even check what tag, class or ID next element have?

if($("#people .making-of .mask ul li.current").next().is('li')) {
    alert("Exists");
}
else {
    alert("Dont exists");
}