Check if element is in viewport check if scrolled to element

gistfile1.txt

//from here https://gomakethings.com/how-to-test-if-an-element-is-in-the-viewport-with-vanilla-javascript/
//NOTE: This script return true when ALL element is in the viewport, not only its part
var isInViewport = function (elem) {
    var bounding = elem.getBoundingClientRect();
    return (
        bounding.top >= 0 &&
        bounding.left >= 0 &&
        bounding.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
        bounding.right <= (window.innerWidth || document.documentElement.clientWidth)
    );
};

if(isInViewport(document.querySelectorAll(".element")[0])){
    //do something when element in viewport
}