jquery detect when id is visible code example

Example 1: jquery see if element is visible

.is(':visible')
//Selects all elements that are visible.

if($('#yourDiv').is(':visible')){
	//do stuff in here
}
//or
$('#yourDiv:visible').callYourFunction();

Example 2: how to detect a section is visible in jquery

$.fn.isInViewport = function() {var elementTop = $(this).offset().top;var elementBottom = elementTop + $(this).outerHeight();var viewportTop = $(window).scrollTop();var viewportBottom = viewportTop + $(window).height();return elementBottom > viewportTop && elementTop < viewportBottom;};