CODEWITHSUNDEEP
javaarrayssortingmethodssyntax
Nicola Daaboul
Nicola Daaboul

Reputation: 77

Why can't I an array in a method outside its class?

I have created the array and outside of its class I have created a method to sort the array. It keeps saying it can't find the variable name of the array I made. When I take the method and put it into the same class as the array it works but it defeats the purpose of what I'm trying to achieve, help?

/**
 * @param args the command line arguments
 */
    public static void main(String[] args) {
        // TODO code application logic here

        System.out.println("Enter a length for the array: ");
        Scanner scan = new Scanner(System.in);
        int x = scan.nextInt();

        int randomNumbers[] = new int[x];

        for (int index = 0; index < randomNumbers.length; index++)

        {
            randomNumbers[index] = (int) (Math.random() * 100);
        }

        for (int index = 0; index < randomNumbers.length; index++)

        {
            System.out.println(randomNumbers[index]);
        }

    }

    static void sortAscending()

    {
        Arrays.sort(randomNumbers);

        for (int i = 1; i < randomNumbers.length; i++) {
            System.out.println("Number: " + randomNumbers[i]);
        }
    }

Upvotes: 0

Views: 1134

Answers (1)

fabian
fabian

Reputation: 82461

Since randomNumbers is declared in the main method, other methods can't access it. There are several ways to make the array accessible from the other method, e.g.:

  1. pass as parameter to the method:

    static void sortAscending(int[] randomNumbers) {
    //...
}

    and call sortAscending call from main like this

    sortAscending(randomNumbers);

  2. Pass the value through a field. I wouldn't use a static field however, since there's only one of these fields for all instances. But you could make use a instance of your class and store the value in a non-static field:

    publc class MyClass {

    // declare randomNumbers as field
    private int[] randomNumbers;

    public static void main(String[] args) {
        MyClass o = new MyClass();
        o.localMain(args);

        // you could call sortAscending here like this
        o.sortAscending();
    }

    // you don't really need to pass args, since you don't use it
    public void localMain(String[] args) {
        // TODO code application logic here

        System.out.println("Enter a length for the array: ");
        Scanner scan = new Scanner(System.in);
        int x = scan.nextInt();

        // assing new value to field
        randomNumbers = new int[x];

        for (int index = 0; index < randomNumbers.length; index++)
        {
            randomNumbers[index] = (int) (Math.random() * 100);
        }

        for (int index = 0; index < randomNumbers.length; index++)
        {
            System.out.println(randomNumbers[index]);
        }

    }

    void sortAscending()
    {
        Arrays.sort(randomNumbers);

        for (int i = 1; i < randomNumbers.length; i++) {
            System.out.println("Number: " + randomNumbers[i]);
        }
    }  

}

Upvotes: 2

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