CODEWITHSUNDEEP
javaarrays
Walaa
Walaa

Reputation: 9

variable have not been initialize while I have already did

The problem is :

a program prompts the user to enter a list of six positive integers, and then declares an array of six elements. The program should sort the list’s elements in ascending order. In addition, the program should display both the original and the sorted list.

My code is: 

import java.util.*;

public class q2 {
    static Scanner scan = new Scanner (System.in);
    public static void main (String[] args ) {
     int i;
int [] fList = new int [6];
int [] sList = new int [6];

 System.out.println ("Enter 6 positive integers :");

 for ( i=0 ; i<fList.length ;i++)
 fList[i]=scan.nextInt();

  for( i=0 ; i<fList.length ; i++)//to copy
  fList=sList;

 int min;
 {
 for ( i=0;i<sList.length ; i++)//sort
 min = i ; 
  for (int j=i+1 ; i<sList.length ; i++)
  if (sList[j] < sList[min] )
   min=j;

    int temp=sList[i];
    sList[i]=sList[min];
    sList[min]=temp;
 }

 System.out.println("Original array : ");
 for ( i=0 ; i < fList.length ; i++)
 System.out.println(fList[i] + " ");

 System.out.println();
 System.out.println("Array after sorting :");
 for ( i=0 ; i < sList.length ; i++)
 System.out.println(sList[i] + " ");

}
}

it says :

q2.java:23: variable min might not have been initialized if (sList[j] < sList[min] ) ^ q2.java:27: variable min might not have been initialized sList[i]=sList[min]; ^ 2 errors

while I have already initialize it

Upvotes: 0

Views: 84

Answers (4)

Aram Kocharyan
Aram Kocharyan

Reputation: 20431

You should use braces for all blocks even when they're not needed (at the moment) - otherwise it can get unwieldy. Also you don't really need both i and min, but I left it in.

import java.util.*;

public class q2 {
    static Scanner scan = new Scanner(System. in );
    public static void main(String[] args) {
        int i;
        int[] fList = new int[6];
        int[] sList = new int[6];

        System.out.println("Enter 6 positive integers :");

        for (i = 0; i < fList.length; i++) {
            fList[i] = scan.nextInt();
        }

        //to copy
        for (i = 0; i < fList.length; i++) {
            fList = sList;
        }

        //sort
        for (i = 0; i < sList.length; i++) {
            int min = i;
            for (int j = i + 1; i < sList.length; i++) {
                if (sList[j] < sList[min])
                    min = j;

                int temp = sList[i];
                sList[i] = sList[min];
                sList[min] = temp;
            }
        }

        System.out.println("Original array : ");
        for (i = 0; i < fList.length; i++) {
            System.out.println(fList[i] + " ");
        }

        System.out.println();
        System.out.println("Array after sorting :");
        for (i = 0; i < sList.length; i++) {
            System.out.println(sList[i] + " ");
        }

    }
}

Upvotes: 0

Cyrille Ka
Cyrille Ka

Reputation: 15533

You initialize min inside the for loop. The compiler can not know if sList is empty or not. If it is empty, then the initialization code will not be run. That's why it is complaining that the variable may not have been initialized.

You should initialize your min to some value beforehand.

That begin said, the first for loop after the declaration of min does not make any sense: min will always be equal to sList.length-1 then (and i will be sList.length. You should rethink your logic.

Upvotes: 0

sandymatt
sandymatt

Reputation: 5612

int min;

Give it an initial value.

int min = 0;

Upvotes: 1

Rahul
Rahul

Reputation: 45070

int min;

You've not initialized the min. I can see that you've done min = i ; in the for loop, but that's still conditional(the for may not always execute, say in the case, the array is empty) and that's why the compiler says that. You need to initialize it with a default value

int min = 0;

or assign some value to it outside any if or for, or any conditional statement in that case.

Upvotes: 4

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