CODE EXAMPLE FOR JAVASCRIPT

create multiple buttons in javascript

let i = 1;
let body = document.getElementsByTagName("body")[0];

for (i; i <= 20; i++) {
  let button = document.createElement("button");
  button.innerHTML = 'Button '+i;
  body.appendChild(button);
  button.addEventListener ("click", function() {
    alert(this.innerHTML);
  });
}