Initializing Variable

I have a question about how to write the following code “nicer” without always having to initialize the variable (s = '') first.

a = ['H', 'e, 'l', 'l', 'o']
s = ''
a.each do { |i| s << i }

Try using the reduce.

s = ['H', 'e', 'l', 'l', 'o'].reduce(''){|a, e| a << e}
a = ['H', 'e, 'l', 'l', 'o']
s = a.join