如何在 Ruby 中动态创建局部变量? [英] How do I dynamically create a local variable in Ruby?

问题描述

我正在尝试使用 eval 在 Ruby 中动态创建局部变量并改变局部变量数组.我在 IRB 中这样做.

I am trying to dynamically create local variables in Ruby using eval and mutate the local-variables array. I am doing this in IRB.

eval "t = 2"
local_variables # => [:_]
eval "t"
# => NameError: undefined local variable or method `t' for main:Object
local_variables << "t".to_sym # => [:_, :t]
t
# => NameError: undefined local variable or method `t' for main:Object

推荐答案

你必须使用正确的 binding.例如，在 IRB 中，这将起作用:

You have to use the correct binding. In IRB for example this would work:

irb(main):001:0> eval "t=2", IRB.conf[:MAIN_CONTEXT].workspace.binding
=> 2
irb(main):002:0> local_variables
=> [:t, :_]
irb(main):003:0> eval "t"
=> 2
irb(main):004:0> t
=> 2

这篇关于如何在 Ruby 中动态创建局部变量?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！