为什么我的数组“不能解析为变量”？

Question

static void createArray(String function) {

 int j = 10;
 int results[]; 
 results = new int[j+1];

for (int i = 0; i < j; i++) {

    String stringI = Integer.toString(i);
    int sum = 0;
    function = function.replace("X",stringI);
    String[] Pluses = function.split("\\+");

    for (String multString: Pluses) {

    String[] mults = multString.split("\\*");
        int multAcc = 1;
    for (String num: mults)
        {
        multAcc *= Integer.parseInt(num);
        }
        sum = sum + multAcc;

        }
        results[i] = sum;   
    }
}

public static void main (String args[]) {

Hello, exscuse me for bad formatting, this is my first post on Stackoverflow.

When compiling I encounter an error that says that "results cannot be resolved to a variable". The code is supposed to create an array containing the integer values of the first 10 values of a function that i've written into the console.

    Scanner myScanner = new Scanner(System.in);
    System.out.println("Enter function");

    String function = myScanner.nextLine();
    createArray(function);
    System.out.println(Arrays.ToString(results));

    myScanner.close();
    }

Answer 1

Local variables inside a { ... } are not accessible outside.

static int[] createArray(String function) {
    int j = 10;
    int[] results = new int[j+1];

    for (int i = 0; i < j; i++) {
        String stringI = Integer.toString(i);
        int sum = 0;
        function = function.replace("X", stringI);
        String[] pluses = function.split("\\+");

        for (String multString: pluses) {

            String[] mults = multString.split("\\*");
            int multAcc = 1;
            for (String num: mults)
            {
                multAcc *= Integer.parseInt(num);
            }
            sum += multAcc;

        }
        results[i] = sum;
    }
    return results;
}

    int[] array = createArray(function);
    System.out.println(Arrays.toString(array));

Let the function return the array, and use a new variable at the call.

The above probably will not do what you intended:

• replace replaces all occurrences of the letter X. A second variable?

Answer 2

The Joop Eggen's Answer is correct. But I think that you must to checkout this link Scope of the variables in Java

Answer 3

results is local variable inside createArray() method. In order to solve this issue you can do either of following:

1. Declare results as static member in class
2. Return array of integer from createArray() method.