CODEWITHSUNDEEP
groovy
Breako Breako
Breako Breako

Reputation: 6451

Getting to a list of lists in Groovy

I have an Object MyObject which has a List of ThatObjects where each ThatObject is a list of ThoseObjects.

MyObject {
    List<ThatObject> thatObjects;
}

ThatObject {
    List<ThoseObject> thoseObjects
}

If I have a handle to MyObject, is it possible to get a handle to all thoseObjects in one list joined to together? Without have to iterate and make the joined list myself?

Thanks

Upvotes: 0

Views: 1296

Answers (1)

tim_yates
tim_yates

Reputation: 171054

Given:

class MyObject {
    List thatObjects
}

class ThatObject {
    List thoseObjects
}

We can make a test object of:

def o = new MyObject( thatObjects:[ new ThatObject( thoseObjects:[ 1, 2 ] ),
                                    new ThatObject( thoseObjects:[ 3, 4 ] ) ] )

Then a simple walk through the properties gives us:

assert o.thatObjects.thoseObjects == [ [1, 2], [3, 4] ]

And call flatten to get a single list:

assert o.thatObjects.thoseObjects.flatten() == [ 1, 2, 3, 4 ]

Or, you could use collectMany

assert o.thatObjects.collectMany { it.thoseObjects } == [ 1, 2, 3, 4 ]

Upvotes: 2

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