Get value from string representing local variable [duplicate]

问题

This question already has answers here:

Is there a 'variable_get' method? If not, how can I create my own? (2 answers)

Closed 4 years ago.

I have a local variable name as a string, and need to get its value.

variable = 22
"variable".to_variable?

How can I get the value 22 form the string?

回答1:

You can use eval.

variable = 22
eval("variable")
# => 22 

However eval can be nasty. If you dont mind declaring an instance variable, you can do something like this too:

@variable = 22
str = "variable"
instance_variable_get("@#{str}")
# => 22

回答2:

binding.local_variable_get("variable")
# => 22

回答3:

use eval() method:

variable = 22
eval "variable" #"variable".to_variable?
# => 22

来源：https://stackoverflow.com/questions/30840127/get-value-from-string-representing-local-variable