Ruby 为什么我得到“得到”；未定义的局部变量“；毕达哥拉斯定理计算器？

我用Ruby制作了一个毕达哥拉斯定理计算器，它有一个bug/无法运行。错误是：

undefined local variable or method `a2'

我想知道是否有人能帮忙

puts "Welcome to my pythagorean theorem calculator. This calculator can find the hypotenuse of any right triangle. Please enter side A of your triangle."
a = gets.to_f
puts "please enter side B of your triangle."
b = gets.to_f
a**2 == a2
b**2 == b2
a2 + b2 = a2_b2
puts "The hypotenuse of your triangle is: #{ Math.sqrt(a2_b2)}"

---

您刚刚犯了两个小错误：

puts "Welcome to my pythagorean theorem calculator. This calculator can find the hypotenuse of any right triangle. Please enter side A of your triangle."
a = gets.to_f
puts "please enter side B of your triangle."
b = gets.to_f
a2 = a**2
b2 = b**2
a2_b2 = a2 + b2 
puts "The hypotenuse of your triangle is: #{ Math.sqrt(a2_b2)}"

--

您的变量未定义 您将赋值与相等运算符（

==

）混淆。当您声明：

a**2 == a2

您正在询问Ruby a2是否等于a2变量的值，该变量在示例代码中未定义。如果您打开一个新的Ruby控制台并在没有程序的情况下输入a2，您会在工作中看到相同的错误：

irb(main):001:0> a2
NameError: undefined local variable or method `a2' for main:Object
    from (irb):1
    from /usr/bin/irb:12:in `<main>'

irb(main):001:0> a2
NameError: undefined local variable or method `a2' for main:Object
    from (irb):1
    from /usr/bin/irb:12:in `<main>'

# In the console, paste one stanza at a time to avoid confusing the REPL
# with standard input.

print 'a: '
a = Float(gets)

print 'b: '
b = Float(gets)

c_squared  = a**2 + b**2
hypotenuse = Math.sqrt(c_squared)