要素が画面内にあるかどうかの判定 - Qiitawindow.addEventListener('load', handleEffect()) window.addEventListener('scroll', this.handleEffect()) function handleEffect(){ // get el let target = document.getElementsByClassName('target') for (var i = 0; i < target.length; i++) { console.log('i',i) let t_height = target[i].offsetHeight let t_classN = target[i].className // get target-position => distance from screen-top-position let offsetY =
