title: Java join collections using functor
body: <p>2 collections are given with the same number of elements, say <code>List&lt;String&gt;</code>. What are elegant ways in <code>JAVA</code> to apply a functor on each 2 elements of collections with corresponding indexes?</p>
  
  <p>Say, one example could be:<br>
  <code>List&lt;String&gt; = { "APPLE", "PEAR" };</code><br>
  <code>List&lt;String&gt; = { "BANANA", "ORANGE" };</code></p>
  
  <p>A predicate that joins string together will result in the following <code>List&lt;String&gt;</code>:<br>
  <code>List&lt;String&gt; = { "APPLEBANANA", "PEARORANGE" };</code></p>