How to return value from $.getJSON

I'm having a problem with method using $.getJSON. It's very simple and it looks like that:

function lastID(query) {

  $.getJSON(url+query ,function(json){

    var type_id = json.data;

});开发者_高级运维

    return type_id // doesn't work
}

Could you please tell me how to return type_id to some other value for instance like this:

var returnedID = lastID(query); // this schould me equal to returned type_id from lastID method.

Many thanks for your reply

---

You will need to do something like the following, since you cannot return a value from an asynchronous request. This question has been asked many times. jquery - return value using ajax result on success and jQuery ajax return value

function processType(id){
    ....
}

function lastID(query){
    $.getJSON(url+query ,function(json){
        processType(json.data);
    });
}