====== 03 for文 ======

<box 70% round left orange|for.rb>
<code console>
for i in 1..3 do
  print("i=", i, "\n")
end

print("End")
</code>
</box>

===== 実行 =====
<code console>
 $ ruby for.rb
 i=1
 i=2
 i=3
</code>