Answers for "how to add a on click function in js"

how to add onclick event in javascript

var element = document.getElementById("elem");
element.onclick = function(event) {
  console.log(event);
}

how to create click function in javascript

var x = document.getElementById('container');
//click can also be antother event
x.addEventListener('click', function (x) {
  console.log('hi');
});