java - calling another method from different class

Question

I was practicing java. And I created a method in another class within the same package such that,

class ArraysPractice2{
    
    int n;
    int[] arr = new int[n];
    
    double averageA(int [] arr)
    {
        double ans = 0;
        int added = 0;
        int total = arr.length;
        
        for(int i = 0; i < arr.length; i++)
        {
            added = added + arr[i];
            
        }
        
        ans = added / total;
        
        return ans;
    }
    
}

and then I have a main method has following code,

    ArraysPractice2 aT = new ArraysPractice2();
    
    int[] testArr = new int[10];
    
    for(int i = 0; i < testArr.length; i++)
    {
        testArr[i] = i + 1;
    }
    
    aT.averageA(testArr);

I expected that aT.averageA would give me the average of testArr array. However, it does not give me anything.

What are the issues in here?

I have a feeling that I am not understanding OOP well..

Thank you for your help.

question from:https://stackoverflow.com/questions/65865313/calling-another-method-from-different-class

Answer 1

 aT.averageA(testArr);

You are not receiving/using a value you have got in the line above.

Try this:

double res = aT.averageA(testArr);
System.out.println("aT.averageA(testArr = "+res);

and you should see your value.