ActionScript 3: Determine if Object Property Exists
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The first is using the hasOwnProperty method:
var myObject:Object = {name: 'Jenkins'};
if (myObject.hasOwnProperty('name')) {
// Do something
}
This method is available in any native ActionScript 3 class, but will not be available in your custom classes if they do not extend a native class.
The second method is using the in operator:
var myObject:Object = {name:'Jenkins'};
if ('name' in myObject) {
// Do something
}
In addition to being shorter, it will also work in custom classes. And best of all, it is a little over twice as fast in most circumstances! It is faster both when checking for properties of native ActionScript 3 classes and custom classes, regardless of whether they extend a native class or not.