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digitalmars.D.learn - How to set non-static variable in static method within class

reply Sam Hu <samhu.samhu nospam.com> writes:
Greetings!

How to set value to non-static variable in a static method within a class?

Given below code:

import std.stdio;

class InputDialog
{
	string name;
	

	static string s_name;
	

	static this()
	{
		s_name="";
		
		
		
	}
		
	static string getString(string prompt="Please enter a line of string below",
							string defaultValue="your string here")
	{
		defaultValue=dataFromConsole();//console input
		s_name=defaultValue;
		return s_name;
	}
	
}

int main(string[] args)
{
	string str=InputDialog.getString;
	writefln("You entered %s",str);
	
	return 0;
}

This works.But what if actually I want to set non-static variable name other
than static variable s_name in static method getString(...)?
How can I do that?

Thanks for your help in advance.

Regards,
Sam
Nov 19 2009
parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
Sam Hu wrote:

 Greetings!
 
 How to set value to non-static variable in a static method within a class?
 
 Given below code:
 
 import std.stdio;
 
 class InputDialog
 {
 	string name;
 	
 
 	static string s_name;
 	
 
 	static this()
 	{
 		s_name="";
 		
 		
 		
 	}
 		
 	static string getString(string prompt="Please enter a line of string below",
 							string defaultValue="your string here")
 	{
 		defaultValue=dataFromConsole();//console input
 		s_name=defaultValue;
 		return s_name;
 	}
 	
 }
 
 int main(string[] args)
 {
 	string str=InputDialog.getString;
 	writefln("You entered %s",str);
 	
 	return 0;
 }
 
 This works.But what if actually I want to set non-static variable name other
than static variable s_name in static method getString(...)?
 How can I do that?
 
 Thanks for your help in advance.
 
 Regards,
 Sam


You can't access non-static data from a static method. Non-static data 
is related to an instance of a class, and a static method is not bound 
to any instance.

Why do you want to do that?
Nov 19 2009
next sibling parent reply Sam Hu <samhu.samhu nospam.com> writes:
Ary Borenszweig Wrote:


 
 You can't access non-static data from a static method. Non-static data 
 is related to an instance of a class, and a static method is not bound 
 to any instance.
 
 Why do you want to do that?


Say I want to implement an utility dialog, InputDialog in DFL which is a
subclass of Form,using its static method I can call InputDialog.getString to
retrieve a string from the textbox of this dialog  other than create an
instance of InputDialog,at the mean time I want to customize the caption text
and the prompt message of the InputDialog in the static method
InputDialog.getString.But I can't modify Form.text, (form.)TextBox.text  in the
static method.Currently I have to  use its non-static version of getString
method and create an instance of the dialog each time when I call getString.
Nov 19 2009
parent Rory McGuire <rjmcguire gmail.com> writes:
Sam Hu <samhu.samhu nospam.com> wrote:
 

 Ary Borenszweig Wrote:
 

 
 You can't access non-static data from a static method. Non-static data 
 is related to an instance of a class, and a static method is not bound 
 to any instance.
 
 Why do you want to do that?


 
 Say I want to implement an utility dialog, InputDialog in DFL which is a 


subclass of Form,using its static method I can call InputDialog.getString to 
retrieve a string from the textbox of this dialog  other than create an
instance 
of InputDialog,at the mean time I want to customize the caption text and the 
prompt message of the InputDialog in the static method
InputDialog.getString.But 
I can't modify Form.text, (form.)TextBox.text  in the static method.Currently I 
have to  use its non-static version of getString method and create an instance 
of the dialog each time when I call getString.

 


since non-static data is only created with an instance you would have to use 
some sort of Singleton or something, I suppose.
Nov 20 2009
prev sibling parent Trass3r <mrmocool gmx.de> writes:
 You can't access non-static data from a static method. Non-static data 
 is related to an instance of a class, and a static method is not bound 
 to any instance.


Exactly. The only way would be to have some array of instances somewhere 
to access.
Nov 19 2009