Question

jQuery code:

$(document).ready(function() {
      $('#hit').click(function() {
        $.getJSON("http://search.twitter.com/search.json?q=stackoverflow&callback=?", function(data) {
            alert(data.length);
        });
      });  // #button hit click evnet
});  // document ready

result is undefined.

I navigate the api call manually in browser, it does return me the data.

Why result is undefined with my jQuery getJSON call?

Answer 1

$.getJSON("http://search.twitter.com/search.json?q=stackoverflow&callback=?", function(data) {
     alert(Object.keys(data).length);
 });

The returned data is an object and not an array, so data.length is undefined.

But above procedure is not supported for all browsers. So you can try:

data.results.length

To check that if a key is present in an object (if you’re not sure) it’s better to use:

if( "key" in object) {

}

For you case:

if( "results" in data) {

}

if your query become invalid twitter will response with an error object so to confirm about successful query result you can use:

if("error" in data) {

}

There is another process called hasOwnProperty()

if(data.hasOwnProperty("results")) {

}