Javascript/id

解説 id付与、取得

sample1

sample1code

var s1Class = document.getElementsByClassName("s1Class");
s1Class[0].id = "s1Id";

sample2

s2Div

sample2code

function s2Func(){
  var s2Class = document.getElementsByClassName("s2Class");
  console.log(s2Class[0].id);
}