jQuery对象返回未定义

Question

So, i have a function that is called via a selector

$(window).scroll(function() {
    console.log($("#content div").inview());
});

However it returns undefined. When I return $elems it shows me all correct elements, but when i return $el it gives undefined.

$.fn.inview = function() {

    var $elems = this;

    function getViewportHeight() {
        /*do tsoomething that works*/
        return height;
    }

    var vpH = getViewportHeight(),
    scrolltop = (document.documentElement.scrollTop ?
        document.documentElement.scrollTop :
        document.body.scrollTop);

    // return $elems.toArray();
    $elems.each(function () {
        var $el = $(this)
        height = $el.height() - (vpH / 1.5),
        inview = $el.data('inview') || false,
        topofscreen = scrolltop,
        botofscreen = topofscreen + vpH,
        topofelement= $el.offset().top;

        return $el;


};

Answer 1

inview doesn't have a return statement, so it always returns undefined

When you return $el; you are doing it inside the anonymous function you pass to $elems.each

If you want to return something from inview then you need a return statement in that function. Possibly you want to create an array just before you call each , push $el onto the array each time you go around the loop and then return the array.