练习24: 更多练习–笨方法学ruby在线-昊天SEO

你离这本书第一部分的结尾已经不远了，你应该已经具备了足够的 Ruby 基础知识，可以继续学习一些程序的原理了，但你应该做更多的练习。这个练习的内容比较长，它的目的是锻炼你的毅力，下一个练习也差不多是这样的，好好完成它们，做到完全正确，记得仔细检查。

puts <span class="s2">"Let's practice everything."</span>
puts <span class="s2">"You\'d need to know \'bout escapes with \\ that do \n newlines and \t tabs."</span>

<span class="nv">poem</span> <span class="o">=</span> <span class="s"><<MULTI_LINE_STRING</span>

<span class="s">\tThe lovely world</span>
<span class="s">with logic so firmly planted</span>
<span class="s">cannot discern \n the needs of love</span>
<span class="s">nor comprehend passion from intuition</span>
<span class="s">and requires an explanation</span>
<span class="s">\n\t\twhere there is none.</span>

<span class="s">MULTI_LINE_STRING</span>

puts <span class="s2">"--------------"</span>
puts poem
puts <span class="s2">"--------------"</span>

<span class="nv">five</span> <span class="o">=</span> <span class="m">10</span> - <span class="m">2</span> + <span class="m">3</span> - 6
puts <span class="s2">"This should be five: #{five}"</span>

def secret_formula<span class="o">(</span>started<span class="o">)</span>
  <span class="nv">jelly_beans</span> <span class="o">=</span> started * 500
  <span class="nv">jars</span> <span class="o">=</span> jelly_beans / 1000
  <span class="nv">crates</span> <span class="o">=</span> jars / 100
  <span class="k">return</span> jelly_beans, jars, crates
end

<span class="nv">start_point</span> <span class="o">=</span> 10000
beans, jars, <span class="nv">crates</span> <span class="o">=</span> secret_formula<span class="o">(</span>start_point<span class="o">)</span>

puts <span class="s2">"With a starting point of: #{start_point}"</span>
puts <span class="s2">"We'd have #{beans} beans, #{jars} jars, and #{crates} crates."</span>

<span class="nv">start_point</span> <span class="o">=</span> start_point / 10

puts <span class="s2">"We can also do that this way:"</span>
puts <span class="s2">"We'd have %s beans, %s jars, and %s crates."</span> % secret_formula<span class="o">(</span>start_point<span class="o">)</span>