jquery之getJSON

1. 
$.getJSON("http://api.flickr.com/services/feeds/photos_public.gne?
tags=cat&tagmode=any&format=json&jsoncallback=?", function(data){
$.each(data.items, function(i,item){
$("<img/>").attr("src", item.media.m).appendTo("#images");
if ( i == 3 ) return false;
});
});

   2.$.getJSON("test.js", { name: "John", time: "2pm" }, function(json){
alert("JSON Data: " + json.users[3].name);
});
   3.该函数是简写的 Ajax 函数，等价于：

$.ajax({ url: url, data: data, success: callback, dataType: json });