习题 24: 更多练习

你離這本書第一部分的結尾已經不遠了，你應該已經具備了足夠的 Ruby 基礎知識，可以繼續學習一些程式的原理了，但你應該做更多的練習。這個練習的內容比較長，它的目的是鍛煉你的毅力，下一個習題也差不多是這樣的，好好完成它們，做到完全正確，記得仔細檢查。 ~~~ puts "Let's practice everything." puts "You\'d need to know \'bout escapes with \\ that do \n newlines and \t tabs." poem = <<MULTI_LINE_STRING \tThe lovely world with logic so firmly planted cannot discern \n the needs of love nor comprehend passion from intuition and requires an explanation \n\t\twhere there is none. MULTI_LINE_STRING puts "--------------" puts poem puts "--------------" five = 10 - 2 + 3 - 6 puts "This should be five: #{five}" def secret_formula(started) jelly_beans = started * 500 jars = jelly_beans / 1000 crates = jars / 100 return jelly_beans, jars, crates end start_point = 10000 beans, jars, crates = secret_formula(start_point) puts "With a starting point of: #{start_point}" puts "We'd have #{beans} beans, #{jars} jars, and #{crates} crates." start_point = start_point / 10 puts "We can also do that this way:" puts "We'd have %s beans, %s jars, and %s crates." % secret_formula(start_point) ~~~ ## 你應該看到的結果 ~~~ $ ruby ex24.rb Let's practice everything. You'd need to know 'bout escapes with \ that do newlines and tabs. -------------- The lovely world with logic so firmly planted cannot discern the needs of love nor comprehend passion from intuition and requires an explanation where there is none. -------------- This should be five: 5 With a starting point of: 10000 We'd have 5000000 beans, 5000 jars, and 50 crates. We can also do that this way: We'd have 500000 beans, 500 jars, and 5 crates. $ ~~~ ## 加分習題 1. 記得仔細檢查結果，從後往前倒著檢查，把程式碼朗讀出來，在不清楚的位置加上註釋。 2. 故意將程式碼改爛，執行並檢查會發生什麼樣的錯誤，並且確認你有能力改正這些錯誤。