CSS/Javascript/HTML Basics prepared by Jisoo Yu on Jun 22, 2020 - Keep in mind Others are so good and fast. Am I dumb? Absolutely NOT! You are jst not familiar with the subject. How can I be familiar with the subject? Repeat, Repeat, Repeat The best to way to earn the skill set is to repeat it. Write the comment first what you are trying to achieve. - Tip to know Make the mind-link between the JS and the Browser/HTML - DOM structure - select & manipulate the element var h1 = document.querySelector(“h1”); h1.style.color = “pink”; another example var body = document.querySelector(“body”); var isBlue = false; setInterval(function (){ if (isBlue){ body.style.background = “white”; } else { body.style.background = ‘#349db”; } isBlue=!isBlue; }, 1000); - class and id class 는 다른 element에서도 사용가능. 즉, 하나의 class 를 만들어 다른 element에 적용할 수도 있다는 의미도 됨. 반면 id는 항상 unique해야 함. 다른 element에서 같은 id 이름을 사용할 수 없음. - element background color change element