When access to Ajax .responseText in an alert it can be displayed, however it cannot be stored in a variable or

var response_var=""; // Added for debugging purposes

ajax.onreadystatechange = function() {
    if (ajax.readyState == 4 & ajax.status == 200) {
        response_var = ajax.responseText;
        alert(ajax.responseText); // This alerts properly (some text).
        return ajax.responseText; // This is returning as undefined
    }
}

return response_var; // This is empty if I add line 1, if not in console it gives error response_var is not defined.

Why isn't the response being stored in the variable or returned? It seems like the scope of response_var ends within the onreadystatechange function so I tried using return. However, the value remains undefined.

Answer №1

When it comes to Ajax, things tend to happen out of sync with the regular flow of code. This is why it's called "Asynchronous JavaScript and XML". For tasks that require Ajax events, it's important not to wait for a return value. Instead, carry on with your task as soon as you receive the response from AJAX.

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