如何在 Google Apps 脚本中引用数组中的元素

Question

This is very basic, but I'm struggling to find the documentation for this.

For example, I need to get a file id based on the file name. Note that this is a simplified example and I may have more than one element in the array.

function getFileID() {
  var fileNames = ["my_file"];
  var Ids = [];
  Ids.push(fileNames.getId());
  Logger.log(Ids)
}

This will return TypeError: Cannot find function getID in object ["my_file"] .

So, it's reading fileNames as an entire object and not just the string value that it contains.

I tried the following, but these aren't right either.

function getFileID() {
  var fileNames = ["my_file"];
  var Ids = [];
  Ids.push(fileNames[1].getId());
  Logger.log(Ids)
}

function getFileID() {
  var fileNames = ["my_file"];
  var Ids = [];
  var fileNames = (JSON.stringify(fileNames));
  Ids.push(fileNames.getId());
  Logger.log(Ids)
}

Answer 1

The reason it is not in the documentation is it is a JavaScript error. Strings and arrays do not have a getId() function. Google documents have a getId() function, but the string is not a google document, just a piece of text that contains the name of the google document.

You need to use drive app to the a document based on it's name, then you can get the ID:

function getFileID() {
  var fileNames = ["my_file"];
  var filename = fileNames[0]; //arrays start at 0
  //this will get the id of the first file with that name
  var file = DriveApp.getFilesByName(filename).next()
  var id = file.getId();
  var Ids = [];
  Ids.push(id);
  Logger.log(Ids)
}

Answer 2

Try changing this:

function getFileID() {
  var fileNames = ["my_file"];
  var Ids = [];
  Ids.push(fileNames.getId());
  Logger.log(Ids)
}

To something like this:

function getFileID() {
  var folder=DriveApp.getFolderById("Folder Id");//might want to limit search to a folder
  var fnA=["Linked 1","Linked 2","Linked 3","Linked 4","Linked 5"];//filenames I picked some names that I had in a folder
  var ids=[];//array to collect names and ids
  for(var i=0;i<fnA.length;i++) {
    var files=folder.getFilesByName(fnA[i]);//often more than one file may have the same name
    while(files.hasNext()) {
      var file=files.next();
      ids.push({name:fnA[i],id:file.getId()});//storing name and file id in each array element.
    }
  }
  var html="";//building a dialog to view results
  for(var i=0;i<ids.length;i++) {
    html+=Utilities.formatString('<br />Filename: %s id: %s',ids[i].name,ids[i].id);
  }
  var userInterface=HtmlService.createHtmlOutput(html).setWidth(800);
  SpreadsheetApp.getUi().showModelessDialog(userInterface, "File names and ids");
}