练习21: 函式的返回值–笨方法学ruby在线-昊天SEO

你已经学过使用=给变量命名，以及将变量定义为某个数字换字符串。接下来我们将让你见证更多奇迹。我们要示范给你的是如何使用=来将变量设置为「一个函式的值」。有一件事你需要特别注意，但待会再说，先输入下面的脚本吧：

def add<span class="o">(</span>a, b<span class="o">)</span>
  puts <span class="s2">"ADDING #{a} + #{b}"</span>
  a + b
end

def subtract<span class="o">(</span>a, b<span class="o">)</span>
  puts <span class="s2">"SUBTRACTING #{a} - #{b}"</span>
  a - b
end

def multiply<span class="o">(</span>a, b<span class="o">)</span>
  puts <span class="s2">"MULTIPLYING #{a} * #{b}"</span>
  a * b
end

def divide<span class="o">(</span>a, b<span class="o">)</span>
  puts <span class="s2">"DIVIDING #{a} / #{b}"</span>
  a / b
end

puts <span class="s2">"Let's do some math with just functions!"</span>

<span class="nv">age</span> <span class="o">=</span> add<span class="o">(</span>30, 5<span class="o">)</span>
<span class="nv">height</span> <span class="o">=</span> subtract<span class="o">(</span>78,4<span class="o">)</span>
<span class="nv">weight</span> <span class="o">=</span> multiply<span class="o">(</span>90, 2<span class="o">)</span>
<span class="nv">iq</span> <span class="o">=</span> divide<span class="o">(</span>100, 2<span class="o">)</span>

puts <span class="s2">"Age: #{age}, Height: #{height}, Weight: #{weight}, IQ: #{iq}"</span>

<span class="c"># A puzzle for the extra credit, type it in anyway.</span>
puts <span class="s2">"Here is a puzzle."</span>

<span class="nv">what</span> <span class="o">=</span> add<span class="o">(</span>age, subtract<span class="o">(</span>height, multiply<span class="o">(</span>weight, divide<span class="o">(</span>iq, 2<span class="o">))))</span>

puts <span class="s2">"That becomes: #{what} Can you do it by hand?"</span>