您正在调用异步
$.get()方法，该异步方法将在您的
getPicsInFolder()函数返回后调用其回调函数。请遵循以下示例中的注释：
function getPicsInFolder(folder) { return_data = "error"; // Since the $.get() method is using the asynchronous XMLHttpRequest, it // will not block execution, and will return immediately after it is called, // without waiting for the server to respond. $.get("getpics.php", function (data) { // The pre here will be executed only when the server returns // a response to the "getpics.php" request. This may happen several // milliseconds after $.get() is called. return_data = data; }); // This part will be reached before the server responds to the asynchronous // request above. Therefore the getPicsInFolder() function returns "error". return return_data;}您应该考虑以某种方式重构代码，以便在
$.get()回调中处理JSON对象的逻辑。例：
$.get("getpics.php?folder=test", function (data) { // Handle your JSON data in here, or call a helper function that // can handle it: handleMyJSON(data); // your helper function});
