--- oct

    ʸ 8 ʸǤȲᤷơѴޤ

        p "10".oct  # => 8
        p "010".oct # => 8
        p "8".oct   # => 0

    oct ʸƬ("0", "0b", "0B", "0x", "0X")˱ 8 
    ʰʳѴԤޤ

        p "0b10".oct  # => 2
        p "10".oct    # => 8
        p "010".oct   # => 8
        p "0x10".oct  # => 16

    ȤߤʤʤʸФޤǤѴоݤȤޤѴоݤ
    ʸǤ 0 ֤ޤ
    


        p "1_0_1x".oct   # => 65

    hex, to_i, to_f, 
    Integer, Float 
    ⻲ȤƤ

    դˡͤʸѴˤ 
    sprintf,
    %,
    Integer#to_s [Integer/to_s]
    Ѥޤ

