动态预言果然动态

def calculate(op1,operator,op2)
  str=op1.to_s+operator+op2.to_s
  eval(str)
end
alpha = 25
beta = 14
puts(calculate(alpha,"+",beta))

puts "Method name:"
meth_name=gets
puts "Lines of codes:"
code = gets
string=%[def #{meth_name}\n #{code}\n end]
eval(string)
eval(meth_name)

Ruby way里的例子代码，动态语言果然动态。