each vs for Ruby

Using each keeps your iterator variable within scope:

["apple", "banana", "pomegranate"].each { |fruit| }

fruit # => NameError! undefined variable

Whereas for leaves a dangling iterator variable:

for fruit in ["apple", "banana", "pomegranate"] do
    fruit
end

fruit # => "pomegranate"

See loops - "for" vs "each" in Ruby - Stack Overflow