I'm thinking about a question, that is : Several classes will have a method
in a same name (probably do same thing too).
then in a program I want the method calling class name coming from a
variable( or maybe a result of a expr).
for example:
class A
def abc end
end
class B
def abc end
end
#what i want to do is something like
a = a_variable.abc # a_variable = A | B
Now I'm doing this by
a = eval(" #{a_variable}.abc ")
My question is, is there any better (or nicer) way to doing this?
With how you asked your question, I'm assuming you want to call a static
method. Otherwise, what's the point of the eval. So, is something like this
what you are after:
class A
def A.abc
"fu"
end
end
class B
def B.abc
"bar"
end
end
With this, there are a couple ways to do this. One, have your variable hold
the constant:
var = A
var.abc -> "fu"
var = B
var.abc -> "bar"
If the variable holds the class name as a string, or symbol, you can fetch the
constant:
var = 'A'
Kernel.const_get(var).abc -> "fu"
var = :B
Kernel.const_get(var).abc -> "bar"
···
On Wednesday 19 August 2009 12:07:06 pm Im still wrote:
Hi all
I'm thinking about a question, that is : Several classes will have a method
in a same name (probably do same thing too).
then in a program I want the method calling class name coming from a
variable( or maybe a result of a expr).
for example:
class A
def abc end
end
class B
def abc end
end
#what i want to do is something like
a = a_variable.abc # a_variable = A | B
Now I'm doing this by
a = eval(" #{a_variable}.abc ")
My question is, is there any better (or nicer) way to doing this?
Hi Spox
Ye, they should be static methods, else it will be wrong. My mistake :DThanks
very much, what you told is exactly what I want !
···
2009/8/20 spox <spox@modspox.com>
On Wednesday 19 August 2009 12:07:06 pm Im still wrote:
> Hi all
>
> I'm thinking about a question, that is : Several classes will have a
method
> in a same name (probably do same thing too).
> then in a program I want the method calling class name coming from a
> variable( or maybe a result of a expr).
>
> for example:
>
> class A
> def abc end
> end
>
> class B
> def abc end
> end
>
> #what i want to do is something like
>
> a = a_variable.abc # a_variable = A | B
>
> Now I'm doing this by
>
> a = eval(" #{a_variable}.abc ")
>
> My question is, is there any better (or nicer) way to doing this?
>
> Thanks
With how you asked your question, I'm assuming you want to call a static
method. Otherwise, what's the point of the eval. So, is something like this
what you are after:
class A
def A.abc
"fu"
end
end
class B
def B.abc
"bar"
end
end
With this, there are a couple ways to do this. One, have your variable hold
the constant:
var = A
var.abc -> "fu"
var = B
var.abc -> "bar"
If the variable holds the class name as a string, or symbol, you can fetch
the
constant:
var = 'A'
Kernel.const_get(var).abc -> "fu"
var = :B
Kernel.const_get(var).abc -> "bar"
Am Donnerstag, 20. Aug 2009, 04:07:06 +0900 schrieb Im still:
>
> a = eval(" #{a_variable}.abc ")
>
> My question is, is there any better (or nicer) way to doing this?
