通过构造函数传递数组

Question

This is what I have so far:

import java.util.*;

public class SArray {

    private int[] array;

    public SArray(int a[]) {
        this.array = a;
    }

    public String toString() {
        String arrayString = "";
        int i = 0;
        while (i < array.length) {
            arrayString = arrayString + array[i];
            i++;
        }
        return arrayString;
    }

    public static void main(String[] args) {
        SArray tester = new SArray(new int[] { 23, 17, 5, 90, 12, 44, 38, 84,
                77, 3, 66, 55, 1, 19, 37, 88, 8, 97, 25, 50, 75, 61, 49 });
        tester.toString();
    }
}

I looked up how to pass arrays through a constructor and this is what I came up with but no values actually go into the array and Im wondering why?

Answer 1

The values are going into the array but you're doing nothing with them. Probably you want/need to display the values, so use System.out.println

public static void main(String[] args) {
    SArray tester = new SArray(new int[] {23, 17, 5, 90, 12, 44, 38, 84, 77, 3, 66, 55, 1, 19, 37, 88, 8, 97, 25, 50, 75, 61, 49});
    //now you're doing something with the value of toString
    System.out.println(tester);
}

Answer 2

The array is there... look:

public static void main(String[] args) {
        NewClass tester = new NewClass(new int[]{23, 17, 5, 90, 12, 44, 38, 84,
            77, 3, 66, 55, 1, 19, 37, 88, 8, 97, 25, 50, 75, 61, 49});
        for(int i = 0; i < tester.array.length; i++){
            System.out.println(tester.array[i]);
        }
    }

this is the output:

23, 17, 5, 90, 12, 44, 38, 84, 77, 3, 66, 55, 1, 19, 37, 88, 8, 97, 25, 50, 75, 61, 49,