Java: passing variable one time but different values

Question

I'm a Java newbie and I have this question.

Can I pass a variable to a method multiple times without creating a new object?

For example, if I have a variable x which is the user input, another variable called m and a method were: if x is "h" then m is "example1" else if x is "f" m is "example2".

If I write:

String x = Scanner.next();

And I create the object passing the x variable, when I write,

System.out.println(obj.m);

If the input was h It will print out "example1"

But if write down this after what i showed up:

x = Scanner.next();
System.out.println(obj.m);

Whatever character I write down the output will be "example 1"

If I type "f" the first time the output will be "example2" But the second system.out.println() will print "example2" eventually if I typed "h" the second time

So is it possible to pass a variable only one time with a value that changes over time without creating a new object?

Your question does not make sense. We don't know what obj is. Post a MCVE. — Elliott Frisch
– Elliott Frisch, Commented Nov 10, 2018 at 20:32
can you show the logic of how "m" is assigned a value? most probably, you need to evaluate the m assignment everytime you change the value of x — dubes
– dubes, Commented Nov 10, 2018 at 20:37

SahilMak · Accepted Answer · 2021-03-02 21:14:26Z

2

If I understand your question correctly, then yes, you can pass a variable to a method multiple times without creating a new object. Let's say you create a class like this:

public class Test {
    public String m;
    
    public void testMethod(String x) {
        if ("h".equals(x)) {
            m = "example1";
        } else if ("f".equals(x)) {
            m = "example2";
        } else {
            m = "other";
        }
    }
}

If you created an object from this class in a main method and pass in different values of x as the argument for testMethod(), the value of m would change:

public class MainClass {
    public static void main(String[] args) {
        Test obj = new Test();
        
        String x = "h";
        obj.testMethod(x);
        System.out.println(obj.m); // prints example1
        
        x = "f";
        obj.testMethod(x);
        System.out.println(obj.m); // prints example2
    }
}

edited Mar 2, 2021 at 21:14

answered Nov 10, 2018 at 20:52

SahilMak

14811 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Francisco Delmar Kurpiel Over a year ago

Instead of x.equals("h") I always use "h".equals(x), because it works even if x is null. No NullPointerException.

Akk Over a year ago

Thank you so much for the answer! But would a "Setter" method do tthe trick as well?

Sandeepa · Accepted Answer · 2018-11-10 20:52:03Z

As I understood your question, I have added a solution that will create the object you mentioned one time and call the method inside it repeatedly as you enter values. This might help you

import java.util.Scanner;

public class A {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        ClassOfYourObject object = new ClassOfYourObject();
        while (true) {
            System.out.print("Enter letter : ");
            String x = scanner.next();
            object.yourMethodToPrint(x);
        }
    }
}

class ClassOfYourObject {
    void yourMethodToPrint(String value) {
        if (value.equals("h")) {
            System.out.println("example1");
        } else if (value.equals("f")) {
            System.out.println("example2");
        } else {
            System.out.println("Invalid letter");
        }
    }
}

Collectives™ on Stack Overflow

Java: passing variable one time but different values

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related