如果您的真实代码是这样的结构，那么您在尝试访问尚未设置的数据时会遇到问题尚未.仅仅因为您的 $.getJSON() 高于 console.log() 并不意味着您在记录数据值之前得到响应.

If your real code is structured like that then you have a problem with trying to access the data that hasn't been set yet. Just because your $.getJSON() is above console.log() doesn't mean that you get the response before you log value of data.

因此，您的问题不在于范围，而在于时机:引入一些服务器端延迟，您的解决方案也可能崩溃.

So your problem is not scope, but rather the timing: introduce some server-side lag and your solution may as well crash.

如果收到回复，也许你应该设置一些标志:

Maybe you should set some flag if response was received:

var data, dataReceived = false;

$.getJSON("panorama.json",function(json){
  data = json.images[0].src;
  dataReceived = true;
  console.log(data);                    
});


// somwhere later
if (dataReceived) {
  console.log(data);
} else {
  // you could use setTimeout() or setInterval here to re-check
  console.log("data not received yet");
}