How to determine if an associative array has a key?

Question

In ActionScript 3, is there any convenient way of determining if an associative array (dictionary) has a particular key?

I need to perform additional logic if the key is missing. I could catch the undefined property exception, but I'm hoping that can be my last resort.

Answer 1

var card:Object = {name:"Tom"};  trace("age" in card);  //  return false  trace("name" in card);  //  return true 

Try this operator : "in"

Answer 2

hasOwnPropery is one way you test for it. Take this for example:

 var dict: Dictionary = new Dictionary();  // this will be false because "foo" doesn't exist trace(dict.hasOwnProperty("foo"));  // add foo dict["foo"] = "bar";  // now this will be true because "foo" does exist trace(dict.hasOwnProperty("foo"));