Ruby 字符串连接和三元不玩得好吗？

Question

在下面的代码中，第三行错误:TypeError: 无法将 false 转换为 String

line = "some default text"
line << " some more text" unless more.empty?
line << (even_more.empty?) ? " done." : " and even more text"

执行此操作的更好方法是什么？

Answer 1

这些括号是必需的，因为 <<优先级高于 ? (precedence table)。解决方案:

line << (even_more.empty? ? " done." : " and even more text")

作为旁注，请注意在构建数组时可以采用函数式方法:

line = [
  "some default text",
  ("some more text" unless more.empty?),
  even_more.empty? ? "done." : "and even more text",
].compact.join(" ")