--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/1-Ruby/day2.rb	Wed Jan 04 21:01:13 2017 +0000
@@ -0,0 +1,61 @@
+#! /usr/bin/env ruby
+
+## File handling with a block
+name = 'day2.txt'
+
+def print_file(name)
+	File.open(name, 'r') do |file|
+		puts name
+		while line = file.gets
+			puts "  #{line}"
+		end
+	end
+end
+
+File.open(name, 'w') do |file|
+	file.puts "File contents go here"
+end
+print_file(name)
+File.open(name, 'r+') do |file|
+	# If we don't seek then we override
+	file.seek(0, IO::SEEK_END)
+	file.puts 'Extra content here'
+end
+print_file(name)
+File.delete(name)
+
+puts "File still exists!" if File.exists?(name)
+
+# Old-skool Java style without passing a code block
+my_file = File.open(name, 'w')
+my_file.puts 'Non-block file content'
+my_file.close() #Note: Close the file manually!
+print_file(name)
+File.delete(name)
+
+## Converting a hash into an array
+my_hash = { 'a' => 'one', 'b' => 'two', 'c' => 'three' }
+puts my_hash.inspect
+# "{}.methods" includes "to_a" method - appears to convert to an array.
+puts my_hash.to_a.inspect
+# However, it includes keys *and* values (as nested arrays, according to http://apidock.com/ruby/Hash/to_a).
+# There's also ":keys" and ":values"
+puts my_hash.keys.inspect
+puts my_hash.values.inspect
+# Alternatively, :collect runs over all key-value pairs as an array, so we can do:
+puts my_hash.collect { |val| val[1] }.inspect
+
+## Converting an array to a hash
+# Arrays have a :to_h method, but that assumes nested arrays of key-value pairs,
+# e.g. [[key1, value1], [key2, value2]]
+# Looping to create a nested array structure then :to_h would work:
+my_array = ['one', 'two', 'three']
+temp = []
+# This would be neater with :map or :collect but then we don't get the index.
+# The only sensible option is an :each_with_index, but that negates the need
+# for :to_h.
+my_hash = {}
+my_array.each_with_index do |val, idx|
+	my_hash[idx] = val
+end
+puts my_hash.inspect