Add Create A Hash From An Array Of Arrays as a ruby til

ruby/create-a-hash-from-an-array-of-arrays.md

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+# Create A Hash From An Array Of Arrays
+
+The `::[]` method on the `Hash` class allows you to succinctly create a hash
+from an array of arrays -- or rather an array of tuples which are key value
+pairs.
+
+```ruby
+> Hash[ [["a",2],["b",4]] ]
+{"a"=>2, "b"=>4}
+> Hash[ [[1,2],[3,4]] ]
+{1=>2, 3=>4}
+```
+
+See the [`Hash::[]`
+docs](http://ruby-doc.org/core-2.3.0/Hash.html#method-c-5B-5D) for more
+details.