将变量传递给函数时，我得到“无效参数”，但是当我硬编码时，它可以在 Apps 脚本中工作

这是我的测试功能：

var testFolderId = 'di98kjsdf9...';
function testGetFolder(testFolderId){
  folder = DriveApp.getFolderById(testFolderId);
  Logger.log("folders: " + folder);
}

当我这样做时它失败了。错误提示：参数无效

但是，如果我将 id 硬编码到“DriveApp.getFolderById”函数中，它就可以工作。

有什么解释吗？这对我来说毫无意义。

当直接从脚本编辑器/菜单/按钮单击/触发器调用函数时，会发生以下操作序列：

• 首先，加载整个脚本并执行所有全局语句。这相当于加载一个网页，其中包含脚本标签中的所有脚本：<script>...code.gs..</script>

• 您调用的函数被调用。这就像添加callMyFunction()在已加载脚本的底部。

• 除了触发器的情况外，您调用的函数将在不传递任何参数的情况下运行。因此所有的论点都是undefined

注意⚠️：如果该函数是由触发器调用的，则传递的第一个参数通常是事件对象，而其余参数未定义。

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 

解决方法：

• Use 默认参数 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/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"

• 如果使用全局变量，则不应声明参数。

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"

进一步阅读：

• Scope https://developer.mozilla.org/en-US/docs/Glossary/Scope
• Closures https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures
• 默认参数 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Default_parameters
• Hoisting https://developer.mozilla.org/en-US/docs/Glossary/Hoisting
• 事件对象 https://developers.google.com/apps-script/guides/triggers/events