I've made a JavaScript library that retrieves a Google Spreadsheet. It's something like Sheetrock.js, while mine is just a less powerful prototype.I've uploaded the source code and example in GitHub. But you can just see the implementation and demo in JSFiddle. A sample spreadsheet is here.Since I am not not a JavaScript professional, it just works, but I have no idea whether there is a misuse of JavaScript or a potential risk.Can anyone give me a useful advice? I am focusing on a sort of violation of JavaScript standard or mechanism rather than a logical error on a flow.spreadcell.js (My library)function SpreadCell(params) {  var is_undef = function(a) {    return typeof(a) == undefined  }  if (is_undef(window.jQuery)) throw jQuery must be loaded.  if (is_undef(params.id)) throw ID of the Google Spreadsheet must be specified.  if (typeof(params.callback) != function) throw Callback must be a function.  var table = {contain_header: !!params.contain_header}  $.ajax({    url: (https://spreadsheets.google.com/feeds/cells/        + params.id + / + (params.sheet || od6)        + /public/basic?alt=json),    success: function(response) {      if (is_undef(response.feed)) throw Invalid response. Maybe API changed.      var get_RC = function(entry) {        var idx = entry.id.$t.lastIndexOf(/);        if (idx == -1) throw Malformed entry. Maybe API changed.;        return entry.id.$t.substr(idx + 2).split(C).map(Number);      }      var data = response.feed.entry      var len = data.length      table.dim = get_RC(data[len - 1])      var raw = [];      for (var i = 0; i < table.dim[0]; i++) {        raw[i] = new Array(table.dim[1])      }      for (var i = 0; i < len; i++) {        var RC = get_RC(data[i]);        raw[RC[0] - 1][RC[1] - 1] = data[i].content.$t;      }      table.name = response.feed.title.$t      if (table.contain_header) table.header = raw.slice(0, table.contain_header)      table.body = raw.slice(table.contain_header)      table.dim[0] -= table.contain_header      delete table.contain_header      params.callback(table)    }  })  return table}index.html (Test sample)<head><title>spreadcell.js</title><script src=https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js></script><script src=https://gsongsong.github.io/spreadcell-js/js/spreadcell.js></script><script>var callback = function(obj) {  console.log(obj)  console.log(news)}</script></head><body><script>var news = new SpreadCell({id: 17EwNIgGf9YqVUgl0WQftCJybGy2cYlKk7PKeJi0T3qU,                          contain_header: false,                          callback: callback});</script></body>
Retrieving Google Spreadsheet
javascript;google sheets