Java-随机生成的数组值的质数之和

Question

I am a beginner in Java and I have a task to do, to calculate the sum of prime numbers from the random-generated values of an array.

So, I was told that I should have 3 classes:

1) MyArray - where I have already written this code:

...
public int[] createArray(int n) {
    int[] a = new int[n];

    for (int i = 0; i < a.length; i++) {
        a[i] = rnd.nextInt(10);
    }
    return a;
}
...

2) IsPrime - where I should do the checking if a number is a prime or not. The problem is I don't know how to 'connect' the array from MyArray to the IsPrime class. I started with a boolean method checkPrime, that has an object m from the MyArray class as a parameter, but I don't know how to continue, how to access the array from the IsPrime class.

I am thankful for any given opinions and advice. Thank you!

PS My third class Run.java has the main-method.

Answer 1

It should basically look like that:

MyArray myArray = new MyArray();
IsPrime isPrime = new IsPrime();

int sum = 0;
for(int num : myArray.createArray(20)){
    if(isPrime.checkPrime(num)){
        sum += num;
    }
}

System.out.println(sum);

Put it into your main method in Run class

Answer 2

You can call IsPrime method from Run Class like below

Class Run {

    public static void main(String[] args]) {

        IsPrime ip=new IsPrime();

        int sum= ip.checkPrime();

        System.out.print(sum);

    }
}


Class IsPrime {    
    public int checkPrime(int length){ MyArray m=
    MyArray ();  int[] arr = m.createArray(5);

    //iterating arr and call to isPrime() method

    }

    public boolean isPrime(int num){ 

        // prime checking logic  
    }  
}

Answer 3

You should declare in the class where you have the array. In the class isPrime, you should declare a method that sums all the prime number, received in the parameter int[]. Just as an idea, and to be quicker, you can use ForkJoinPool to create multiple Threads, but I think that is not your main target for the moment.

    public class YourClass{

        private int[] MyArray;

    //Constructor
    //Methods

    //Getter of MyArray
        public int[] getMyArray(){
            return this.MyArray;
        }
    };