×
INTELLIGENT WORK FORUMS
FOR COMPUTER PROFESSIONALS

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Passing parameters back and forth

Passing parameters back and forth

Passing parameters back and forth

(OP)
How do I pass multiple parameters back and forth between main and subroutine?  Say I have the following program.


public class test {
    public static void main(String[] args) {
        char a=' ';
        int b=1;
        sub(a,b);
        System.out.print(a +" " +b);
    }
    static void sub(char a,int b) {
        a='h';
        b=15;
        return new Object(a,b);
        
    }

}
 Obviously, the ouput isn't going to be "h 15".  What do I need to change for a and b to be passed back to main?

PS - I must say I am frustrated by java.

RE: Passing parameters back and forth

A Java method cannot return more than one parameter. You would need to encapsulate them in a new class or maybe use a Vector

Cheers,
Dian

RE: Passing parameters back and forth

(OP)
In other words, java sucks.  I should have known this when I started learning it.   

RE: Passing parameters back and forth

Well, or maybe you suck? When you return something (last line):

CODE

    static void sub (char a,int b) {
        a='h';
        b=15;
        return new Object (a,b);   
    }
you have to declare it:

CODE

    static Object sub (char a,int b) {
        a='h';
        b=15;
        return new Object (a, b);   
    }
But here the compiler will have a reason to complain: There is no constructor for object which takes 2 parameters. You may use a self defined Object CI, and declare to return that:

CODE

    class CI {
        char c;
        int i;
        new CI (char c, int i) {
            this.c = c;
            this.i = i;
        }
    }

    static CI sub (char a,int b) {
        a = 'h';
        b = 15;
        return new CI (a, b);   
    }

To use that object, you have to assign the result of your methodcall to an object:

CODE

    public static void main (String[] args) {
        char a = ' ';
        int b = 1;
        CI ci = sub (a, b);
        System.out.print (ci.a + " " + ci.b);
    }
 

don't visit my homepage: http://home.arcor.de/hirnstrom/minis/index.html

RE: Passing parameters back and forth

(OP)
Yes, I do suck.  I can't get your example to compile.


public class test {
    public static void main (String[] args) {
        char a = ' ';
        int b = 1;
        CI ci = sub (a, b);
        System.out.print (ci.a + " " + ci.b);    
    }
    
    class CI {
        char c;
        int i;
        new CI (char c, int i) {
            this.c = c;
            this.i = i;
        }
    }
    
    static CI sub (char a,int b) {
        a = 'h';
        b = 15;
        return new CI (a, b);
    }
}
 

RE: Passing parameters back and forth

Yes, you're right in 3 ways:
a) The CTOR can have a visibility modifier like 'public, private, protected' or nothing but not new (CI).
b) I didn't make visible, that the static method 'sub' needs a surrounding class.
c) I named ci.c and ci.i in the main-method ci.a and ci.b.
This is now a compilable file:

CODE

class CI {
    char c;
    int i;
    
    CI (char c, int i)
    {
        this.c = c;
        this.i = i;
    }
}

public class CiTest
{
    static CI sub (char a, int b)
    {
        a = 'h';
        b = 15;
        return new CI (a, b);   
    }

    public static void main (String[] args) {
        char a = ' ';
        int b = 1;
        CI ci = sub (a, b);
        System.out.print (ci.c + " " + ci.i);
    }
}

don't visit my homepage: http://home.arcor.de/hirnstrom/minis/index.html

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members!

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close