The local variable may not have been initialized error

Question

i have fixed it now, but it still shows me 0 after i input my first numbers. it shows me correct on vikt but not in pris. :S

package Brev;

import static javax.swing.JOptionPane.*;

public class Uppgift1 {

    public static void main(String[] arg) {

        String indata = showInputDialog("Hur mycket väger ditt brev i gram?");

        int vikt = Integer.parseInt(indata);
        int pris = 0;

        do {

            indata = showInputDialog("Ditt porto kostar " + pris + " kr med vikten " + vikt + " Gram." +
                    "\nSkriv in en följande vikt för att addera på ditt nuvarande porto.");

            vikt = vikt + Integer.parseInt(indata);



            pris = pris + pris;




        if (vikt < 1) {

            showMessageDialog(null, "Error");
        }

        else if (vikt <= 50){


            showMessageDialog(null, "Portot blir "+ (pris + 7) + "Kr. med " + vikt + " Gram.");
        }

        else if (vikt <= 100){


            showMessageDialog(null, "Portot blir "+ (pris + 14) + "Kr. med " + vikt + " Gram.");
        }

        else if (vikt <= 250){


            showMessageDialog(null, "Portot blir "+ (pris + 28) + "Kr. med " + vikt + " Gram.");
        }

        else if (vikt <= 500){


            showMessageDialog(null, "Portot blir "+ (pris + 42) + "Kr. med " + vikt + " Gram.");
        } 

        else if (vikt <= 1000){


            showMessageDialog(null, "Portot blir "+ (pris + 56) + "Kr. med " + vikt + " Gram.");
        }

        else if (vikt <= 2000){


            showMessageDialog(null, "Portot blir "+ (pris + 70) + "Kr. med " + vikt + " Gram.");
        }

        else if (vikt > 2000)

            showMessageDialog(null, "Maximalvikten är 2000GRAM / 2KG");




        } while (vikt <= 2000);





    }
}

Answer 1

You're writing code that looks ambiguous:

"aString" + anInt + anotherInt + "anotherString"

Java is interpreting this to mean the equivalent of:

("aString" + anInt) + anotherInt + "anotherString"

so that each int is converted to a String before being added, but you wanted to do the equivalent of:

"aString" + (anInt + anotherInt) + "anotherString"

So, just write it in this last, unambiguous way. Put parentheses around your math formulas if they're part of a string addition.