Better way to assign value to array of object in Java

Question

I have a class in Java which has 2 fields like

Class A
{
  int i;
  double v;
}

I make an array of object of class A like:

A[] x = new A[3];

After assigning the memory to object I assign value to object like:

A[0].i = 1;
A[0].v = 2.5;
A[1].i = 2;
A[1].v = 3.5;
A[2].i = 55;
A[2].v = 1.5;

I was wondering it there was a better way to initialize the object-values.

Answer 1

public class A {
int i;
double v;

public A(int ii, double dd) {
    i = ii;
    v = dd;
}

public static void main(String[] args) {

    A[] a = new A[10]; // size
    for (int i = 0; i < a.length; i++) {
        a[i] = new A(1, 1.0);

    }

}
}

You can also fill elements by this way:

A[] a = new A[] { new A(1, 2.5), new A(2, 3.5), new A(55, 1.5) };

Answer 2

Yes: use constructors :

A[] x = new A[]{new A(1, 2.5), ... };

Update: wrt. to comment below:

// Fake constructor
public static A new_A(int i, double v) {
    A x = new A();
    x.i = i;
    x.v = v;
    return x;
}

A[] x = new A[]{new_A(1, 2.5), ... };

Answer 3

Class A
{
  private int i;
  private double v;

 void setI(int i){
  this.i =i;
}
void setV(double v){
  this.v =v;
}
}

After that assign values like A[0].setI(1);Also provide getters for the variables.

Answer 4

Go for setters\\getters and a constructor.

class A {
        int i;
        double v;

        public A(int i, double v) {
            super();
            this.i = i;
            this.v = v;
        }

        public int getI() {
            return i;
        }

        public void setI(int i) {
            this.i = i;
        }

        public double getV() {
            return v;
        }

        public void setV(double v) {
            this.v = v;
        }

    }

And if you init it with those 3 values you might as well do:

A[] x = {new A(1,2.5), new A(2, 3.5), new A(55,1.5)};

Answer 5

Modify ur code as follows

 Class A
    {
      private int i;
      private double v;
    public A(int x,double y)
    {
         i=x;
         v=y;
    }
    }
    class mainclass{
    public static void Main(String []args)
    {
          A[] x = new A[3];
          double i=1,v=2.5;
          for(int i=0;i<2;i++)
          {
             x[i]=new A(i,v);
             i+=1;
             v+=1.0;
          }
          x[3]=new A(55,1.5);
    }