How Can I Avoid Errors When Asynchronously Loading JSON Data with jQuery's $.getJSON()?

Asynchronous JSON Loading

Loading a local JSON file using jQuery's $.getJSON method can sometimes result in unexpected behavior when attempting to access the loaded data. This occurs because $.getJSON executes asynchronously, meaning the subsequent code accessing the data may be executed before the JSON file is fully loaded.

In the example provided:

var json = $.getJSON("test.json");
var data = eval("(" + json.responseText + ")");
document.write(data["a"]);

The eval line fails karena json.responseText is still undefined because the JSON file hasn't been loaded yet.

To resolve this issue, $.getJSON should be handled asynchronously using a callback function:

$.getJSON("test.json", function(json) {
    console.log(json); // Access the loaded data within this callback
});

By implementing this asynchronous approach, the code accessing the JSON data will only execute after the data is fully loaded, ensuring that data is defined and accessible.

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