Answers for "how to delete all li on page in js"

remove all options from select jquery

$('#mySelect')
    .empty()

javascript get all script tags on page

var scripts = document.getElementsByTagName("script");
for (var i = 0; i < scripts.length; i++) {
  if (scripts[i].src) {
  	console.log(i, scripts[i].src);
  } else { 
    console.log(i, scripts[i].innerHTML);
  }
}