Animation js (Alternative wow js)

function isScrolledIntoView(elem) {

    let docViewTop = $(window).scrollTop();

    let docViewBottom = docViewTop + $(window).height();

    let elemTop = $(elem).offset().top;

    let elemBottom = elemTop + $(elem).height();

    return ((elemTop <= docViewBottom) && (elemBottom >= docViewTop));

}

$('.animate').each(function() {

    if (isScrolledIntoView(this) === true) {

        let animation = $(this).attr('data-animation');

        let iteration = $(this).attr('data-iteration');

        let duration = $(this).attr('data-duration');

        let delay = $(this).attr('data-delay');

        $(this).addClass('animated');

        $(this).css({

            'visibility': 'visible',

            'animation-duration': duration,

            'animation-name': animation,

            'animation-delay': delay,

            'animation-iteration-count': iteration,

        });

    }

});

$(window).scroll(function() {

    $('.animate').each(function() {

        if (isScrolledIntoView(this) === true) {

            let animation = $(this).attr('data-animation');

            let iteration = $(this).attr('data-iteration');

            let duration = $(this).attr('data-duration');

            let delay = $(this).attr('data-delay');

            $(this).addClass('animated');

            $(this).css({

                'visibility': 'visible',

                'animation-duration': duration,

                'animation-name': animation,

                'animation-delay': delay,

                'animation-iteration-count': iteration,

            });

        }

    });

});