strToAscii_bookmarklet.js

(function() {
  let c = window.getSelection().toString();
  if (c == ""){
    c = window.prompt("Input character.", "");
  }
  let a = [];
  for (let i of c) {
    a.push(i.charCodeAt());
  }
  alert(a);
})();

// Bookmarlet (compiled with Closure Compiler)
// javascript:function a(){var e=b,f=0;return function(){return f<e.length?{done:!1,value:e[f++]}:{done:!0}}}var c=window.getSelection().toString();""==c&&(c=window.prompt("Input character.",""));var d=[],g,b=c,h="undefined"!=typeof Symbol&&Symbol.iterator&&b[Symbol.iterator];g=h?h.call(b):{next:a()};for(var k=g.next();!k.done;k=g.next())d.push(k.value.charCodeAt());alert(d);