#!/usr/bin/env ruby =begin ********************************************************************** This is a comment block, something you write for the benefit of human readers (including yourself). The interpreter ignores it. There is no need for a '#' at the start of every line. ********************************************************************** =end
組織你的代碼
Ruby讀到什么就處理什么.沒有編譯處理;如果有什么還沒讀到,就被簡單地認為未定義.
# this results in an "undefined method" error: print successor(3),"\n" def successor(x) x + 1 end
# Conversion of fahrenheit to celsius, broken # down into two steps. def f_to_c(f) scale(f - 32.0) # This is a forward reference, but it's okay. end def scale(x) x * 5.0 / 9.0 end printf "%.1f is a comfortable temperature.\n", f_to_c(72.3)
#!/usr/bin/env ruby def main # Express the top level logic here... end # ... put support code here, organized as you see fit ... main # ... and start execution here.
Ruby也提供了將復雜程序分割為可讀,可重用,邏輯相關的大塊的工具.我們已看到用 include 來訪問模塊.你將發(fā)現(xiàn) load 和 require 也很有用.load的作用類似于文件的復制加粘貼(和C的#include處理器指令相似).require更復雜,僅在需要時才加載,而且最多加載一次.load和require還有其它一些區(qū)別;在語言手冊,FAQ中可找到更多信息.
