WTF Is? Array: Length Node in Unreal Engine 4 ( UE4 )

What is the Array: Length Node in Unreal Engine 4

[lyoshko]

Is this Length node cheap?
For example, my blueprint uses length of some array in calculations each tick.
I could avoid that by saving array length to some variable and using that variable instead of getting array length each tick. Is it worth it?

[lunarpooch]

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[inqiazharaziz]

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[jadebrimhall]

So length is kind of like getting the absolute value max of some information.

[tuazulyrojoeljean]

So, Length Node is pretty much the same as Last Index, right? Or is there some difference?

[merronmist]

is there a way to set the length of an array?