单击时弹出无法打开Uncaught TypeError：无法读取未定义的属性“ top”

Question

I face a situation where google chrome returns

Uncaught TypeError: Cannot read property 'top' of undefined

This is my jquery code

$(document).on('click', '.show_popup', function(){
    document.body.style.overflow = "hidden";
    $('body').css('overflow', 'hidden');    
    callAjax($(this).attr('href'), 'mode=ajax', function(t){
        $('.popup-screen').html(t);
        $('.main-overlay').show();

        // $('').raty();
        $('#star').raty({
          click: function(score, evt) {
            $('#review_rating').val( score);
          }
        });
        // window.scroll(0,0);
        $("html, body").animate({ scrollTop: $(".screenTable").offset().top },500);
    });
    return false;
});

Please help and also after error at

XMLHttpRequest.self.xmlHttpReq.onreadystatechange

Answer 1

This error is showing up because element with class .screenTable could not be found.

You can check the existence of element before calling top to prevent error

    var STable = $('.screenTable');
    if (STable.length) //1
    { 
      $("html, body").animate({ scrollTop: $(".screenTable").offset().top },500);
      alert("top");
    }
    else{
    alert("element not found, so no top");
    }

Always wrap your function under $( document ).ready() More info on document.ready

$( document ).ready(function() {

//All elements has been loaded and are available.

});