如何創建一個文件夾，如果它不存在？

Question

我試圖創建一個文件夾，如果它不存在，但代碼每次運行時都會創建一個新文件夾。我不知道我的代碼是否正確。

這裏是我的代碼：

var alumnopath = DocsList.getFolderById ('0Bzgw8SlR34pUbFl5a2tzU2F0SUk'); 
var alumno2 = alumno.toString(); 
Logger.log(alumno2); 
try { 
    var folderalumno = alumnopath.getFolder(alumno2); 
    if (folderalumno == undefined){ 
    var folderalumno = alumnopath.createFolder(alumno2); 
    } 
    else { 
    var folderalumno = alumnopath.getFolder(alumno2); 
    } 
} 
catch(e) { 
    var folderalumno = alumnopath.createFolder(alumno2); 
} 
folderalumno.createFile(pdf.getAs('application/pdf')).rename( alumno + " , " + fechafor); 

感謝您的幫助！

Answer 1

當你使用try/catch結構時，你實際上不需要if條件。 try/catch結構處理文件夾本身不存在的情況。

試試這樣說：

var alumnopath = DocsList.getFolderById ('0Bzgw8SlR34pUbFl5a2tzU2F0SUk'); 
var alumno2 = alumno.toString(); 
Logger.log(alumno2); 
try{ 
    var folderalumno = alumnopath.getFolder(alumno2); 
} 
catch(e) { 
    var folderalumno = alumnopath.createFolder(alumno2); 
} 
folderalumno.createFile(pdf.getAs('application/pdf')).rename( alumno + " , " + fechafor); 

Answer 2

谷歌已經改變了它的腳本。我知道這是一箇舊帖子，但這是我能想出的最佳答案：

function getFolder(parent_folder,folder_name){ 
    var folders = parent_folder.getFolders();  
    while (folders.hasNext()) { 
    var folder = folders.next(); 
    if(folder_name == folder.getName()) {   
     return folder; 
    } 
    } 
    return false; 
} 

var parent_folder = DriveApp.getFolderById(//id\\); 
var folderName = getFolders(parent_folder,name); 
if (folderName === false){ 
    folderName = outputfolderId.createFolder(name); 
} 

希望這可以幫助別人！

Answer 3

由於谷歌Apps腳本代碼在2016年八月

var par_fdr = DriveApp.getFolderById(123456789A); // replace the ID 
var fdr_name = "child_fdr"; 

try { 
    var newFdr = par_fdr.getFoldersByName(fdr_name).next(); 
} 
catch(e) { 
    var newFdr = par_fdr.createFolder(fdr_name); 
}