Can i Pass a variable as a parameter from one method to other method

[Anagha]

Hi All,

I am having two different methos

1. WriteFile(String f,String arrr)
2. ReadFile(file f1, String s1);

I want to pass a variable from ReadFile(file f1, String s1) to the WriteFile(String f,String arrr).

How can i do this please provide me some guidelines.

Thanks In Advance.

[jasonwucinski]

here's an example of a method calling another method and passing it a variable:

    public void methodOne(){
          String varOne = "some string 1";
          String varTwo="some string 2"

         methodTwo(varOne, varTwo);
    }


    public void methodTwo(String one , String two){
        this.jLabel1.setText(one);
        this.jLabel2.setText(two);

    }

hope this helps

[Anagha]

Thanks jasonwucinski,

Can i use varOne Outside the method to pass to methodTwo(), without calling it in methodOne();

[sunde887]

Not if you define it locally(in the method) if you make it a class variable it would work how you want though.

[Anagha]

How can i Use that Local variable outside to the method..

[jasonwucinski]

sure, if its declared as a global variable in your class. like this:

public class MyClass {

   private String varOne = "a";

public void myMethodOne(){
//this method as access to varOne
String NewVar = varOne + "b";
myMethodTwo(NewVar);

}
public void myMethodTwo(String getVar){
//this method as access to varOne which would = "a"
// the passed variable, getVar would = "ab"

}


 
}

is this what you mean? in this example, there is a global variable called VarOne, which all methods in the class can read. Method one takes that variable, appends it with a new string, then passes it to methodTwo. is this what you meant?

[jasonwucinski]

Also, if you need to pass variable between classes, you will need to use an interface, but that's a different, more complicated, topic

[Anagha]

Thanks jasonwucinski, sunde887,

public static void WriteFile(String f, String arr)
{
	try{

	File f1=new File(f);
	f1.createNewFile();
	FileWriter fstream = new FileWriter(f,true);
	BufferedWriter out = new BufferedWriter(fstream);
	out.write(arr);
	out.write(System.getProperty("line.separator"));
	System.out.println("Hello Done");

	out.close();

}catch(Exception e){
e.printStackTrace();
}

This is my one method

public static void ReadFile(File f1, String f2)
{
	Writer output = null;
	//int i=2;
       Sheet sheet;
         try {
				output = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(f2),"UTF8"));
		                sheet = SpreadSheet.createFromFile(f1).getSheet(0);
				int nColCount = sheet.getColumnCount();
				int nRowCount = sheet.getRowCount();

				System.out.println("Rows :"+nRowCount);
				System.out.println("Cols :"+nColCount);
				MutableCell cell = null;

            for(int nRowIndex = 0; nRowIndex < nRowCount; nRowIndex++)
            {
                int nColIndex = 0;
                for( ;nColIndex < nColCount; nColIndex++)
               {
                    cell=sheet.getCellAt(nColIndex, nRowIndex);
				   System.out.print(cell.getValue()+ "");
				   output.write(cell.getValue()+"");
				   output.write(System.getProperty("line.separator"));
				//}
                System.out.println();

           }
             }
	    output.close();
        }catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
		}

And this is Another Method, Now I want to use value of this cell.getValue() as parameter to the WriteFile method. How can i achieve this.

Thanks

[jasonwucinski]

i find it strange you were able to write that code but not be able to understand variable scope. anyway, look how your writeFile method is constructed. it accepts two variables, both strings. one, presumably is the name of a file, im not sure what the other is for. so, you would call WriteFile like this:

WriteFile("MyFilePath://MyFileName", "some string")

so, you could either add another variable to the writeFile like this:

public static void WriteFile(String f, String arr, String AnotherVar)

which means you would call it like this:

WriteFile("MyFilePath://MyFileName", "some string", "one more string")

or, you create a global variable and use that. try reading this, as you wont get far in any programming course without understanding variable and their scope:

Declaring Member Variables (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

[Junky]

How can i achieve this.

Are you serious? You are basically getting people on the forum to write your code line by line. How about you think for yourself.

[sunde887]

I'd like to nitpick and say that it isn't technically a global variable, instead it's an instance variable. It's honestly not a huge difference but global variables in java are more like a static variable.

When you want a variable that can be used in multiple methods you want to give the class an instance variable.

[Junky]

Nitpick the nitpick. Java does not have global variables at all. ;)

[Anagha]

Hi Juncky,

I am not asking to write a code line by line... I am requesting for any one who can suggest me the best way to achieve my goal not the Code.

[sunde887]

Nitpick the nitpick. Java does not have global variables at all. ;)

lol. I like this post.

@op: If you intend to receive advice, and not answers, it's best to show what you tried as well as asking the questions. A lot of people come here "asking" for help, when they really are just looking for the direct answer.

[jasonwucinski]

sorry, most of my programming experience is in the .Net's. global variables or class fields, what's the difference lol.

[Anagha]

Hi sunde887,

So I need to use that variables as a class variable then only i can use into the method.

@ jasonwucinski,

WriteFile("MyFilePath://MyFileName", "some string")

The Second parameter i want to use is that from ReadFile(cell.getValue()+"");

Thanks...

[sunde887]

@Jason, perhaps it's a small difference, however there is absolutely a difference between a class variable and a global one, a global variable is something that can be used by anything directly. A static variable is close to this but still a bit different.

A class variable appears like this inside of the class. However outside of the class it cannot be accessed directly and requires you to first create an instance of the object to use it "globally"

I do, of course understand what you were trying to convey, I just felt like I needed to point out the difference.

[Anagha]

Hi All,

I am Still Confuse that how do i use local variable of one method as parameter for another method.

Please Help me...

Tell me What should i use for this..


Thanks in Advance..

[Junky]

I'm sure you have already been told. You call the method and pass the value as a parameter.

class Foo {
    Bar b = new Bar();

    public void someMethod() {
        int value = 10;
        methodInSameClass(value);
        b.methodInOtherClass(value);
    }

    private void methodInSameClass(int v) {
        System.out.println(2 * v);
    }
}

class Bar {
    public methodInOtherClass(int v) {
        system.out.println(4 * v);
    }
}