When a function is called directly from the script editor/menu/button click/triggers, the following sequence of actions happens:
-
First, Entire script is loaded and All global statements are executed. This is equivalent to loading a web page with all your script in script tags:
<script>...code.gs..</script> -
The function you called is called. This is like adding
callMyFunction()at the bottom of the already loaded script. -
Except in case of triggers, The function you called is run without passing any arguments. Thus all arguments are
undefined
Caution ⚠️: If the function is called by a trigger, the first parameter passed is usually the event object, while the rest of the parameters are undefined.
var testFolderId="1dhhddci6";
//When this function is called by IDE, it called without passing any arguments
function testGetFolder(testFolderId){//<=same as calling `testGetFolder()` or `testGetFolder(null)`
//testFolderId is declared in local scope , but is undefined
folder = DriveApp.getFolderById(testFolderId);//<= testFolderId is undefined
Workarounds:
- Use default parameters:
//When this function is called by IDE, it called without passing any arguments
function testGetFolder(testFolderId="dhhddci6"){//<=same as calling `testGetFolder()`, but `testFolderId` is passed a value. Also same as calling `testGetFolder("dhhddci6")`
//testFolderId is declared in local scope and is defined(declared and intialized with a value)
folder = DriveApp.getFolderById(testFolderId);//<= testFolderId is "dhhddci6"
- If global variables are used, Then the arguments should not be declared.
var testFolderId="1dhhddci6";
//When this function is called by IDE, it called without passing any arguments
function testGetFolder(){//<=same as calling `testGetFolder()`
//testFolderId is NOT declared in local scope, so variable is looked up in global scope(where it is defined)
folder = DriveApp.getFolderById(testFolderId);//<= testFolderId is "dhhddci6"