(Ruby)为什么这样做？

string = "This is a test"
offset = 5

def encode(string, offset)
    coded = ""
    string.scan(/./) do |char|
        numbers = char.ord
        if numbers == 32
            numbers = numbers
        else
            numbers = numbers + offset
        end
        coded << numbers
    end
    return coded
end

puts encode(string, offset)

我得到了所需的编码输出：“Ymnx nx f yjxy”,但我不知道为什么.我期待一串数字,因为我从未指定将这些字母转回字母.有人可以解释一下发生了什么吗？

Append—Concatenates the given object to str. If the object is an Integer, it is considered as a codepoint, and is converted to a character before concatenation. Concat can take multiple arguments. All the arguments are concatenated in order.

原始字符串中的字符转换为序数整数,与偏移量一起添加,然后输入字符串#<<方法.