Is it possible to get variable value using a string containing variable name?

[Kian Peng Yong]

Dear sir,

I have a variable name = home.canvas.color.

String home.canvas.color = "purple";

If I obtain an input from user = "home.canvas.color", is there a way that I can retrieve the value "purple" from the actual variable home.canvas.color?

If so, can you show me please?

Thank you very much.

Best regards,
Yong

[Abimaran Kugathasan]

Kian Peng Yong wrote:
I have a variable name = home.canvas.color.
String home.canvas.color = "purple";

Is this a legal variable name in Java?

[Prasad Krishnegowda]

Abimaran Kugathasan wrote:

Kian Peng Yong wrote:
I have a variable name = home.canvas.color.
String home.canvas.color = "purple";

Is this a legal variable name in Java?

No, its not legal..

[subodh k kumar]

If you have valid variable name then by using refelection API(java.lang.reflect.Field)you can retrieve the expected value.

[Ash Kondhalkar]

Hi,

Try this code.

package src.javaranch;
import java.lang.reflect.Field;
public class Test {
	
	public String variable1 ="purple";

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception{
		// TODO Auto-generated method stub
		Test s1 = new Test();
		//Field[]  f1 = s1.getClass().getDeclaredFields();
		Field f1 = s1.getClass().getField("variable1");
		String str1 = "";		
		System.out.println(f1.get(s1)); // this prints purple
		
	}

}

The variable in your case "home.canvas.color" as to be defined as instance variable in a class. Also since java naming convention doesnt allow "." in its name you need to give some different name. Then you can follow above code to get what you are trying.

Thanks
Ashwin

[Lester Burnham]

Ugh. Why would you want to use reflection? If you need variables of which you do not know the names beforehand, use a Map:

// declare it

Map variables = new HashMap<String,String>();

// populate it

variables.put("home.canvas.color", "purple");

//retrieve a value

String color = variables.get("home.canvas.color");

[Abimaran Kugathasan]

Prasad Krishnegowda wrote:
No, its not legal..

That's why, I've asked!

[Rob Spoor]

Ash, please UseCodeTags next time. I've replaced your asterisk lines with code tags, and not only does it not mess up the forum layout, it also preserves indentation and adds syntax highlighting.

[Kian Peng Yong]

Thank you very much