Testing for undefined and null child objects in ActionsScript/Flex

Programmer Question

Hi Everyone,

I use this pattern to test for undefined and null values in ActionScript/Flex :

if(obj) {
    execute()
}

Unfortunately, a ReferenceError is always thrown when I use the pattern to test for child objects :

if(obj.child) {
    execute()
}

ReferenceError: Error #1069: Property child not found on obj and there is no default value.

Why does testing for child objects with if statements throw a ReferenceError?

Thanks!

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