Question

I have an ArrayList of Foo objects. Foo’s properties are String name and int age.
I don’t want more than one of the same name, so when the same name, keep only the greatest age.
I’m looking an idea to get me going in Java.

Answer 1

1. Create a Hashtable to keep track of the current greatest-aged Foo that you’ve come across.
2. Loop over your ArrayList. For each Foo:
   1. if the Hashtable doesn’t contain an item with the given name, add the item with its name as the key.
   2. if the Hashtable contains a Foo with the given name, check its age.
      1. if the age of the current Foo is greater than the age of the Foo in the Hashtable, replace the Foo in the Hashtable with the one you’re looking at.