I am looking at the code written by someone else. In this a class is added of removed when we reach a particular section.I cannot understand the use of $('body').height() here
if($('#impact_calculator'). length){
$(window).scroll(function () {
var scroll = $(window).scrollTop();
// var box = $('#impact_calculator').offset().top -190;
var box = $('body').height() - $('#impact_calculator').height() - 450;
if (scroll >= box) {
setTimeout(() => {
$("body").addClass("sticky");
}, 500);
} else {
setTimeout(() => {
$("body").removeClass("sticky");
}, 500);
}
});