需要Java阵列帮助

Question

I am building a Java Array where the odd columns will output the #1 and the even columns will output the #0. Here is what i have so far. I'm certain my mistake is trivial but if you could help it would be greatly appreciated!

import java.util.Scanner;
public class TestArray2 {
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);

        int [][] a = new int[5][5];
        for(int i=0; i<a.length;i++){

            for(int j=0;j<a[0].length;j++){
                int x = j;
                if(x%2 == 0){
                    a[i][j] = 0;
                }
                else  {
                    a[i][j] = 1;
                }
            }
            input.close();
        }
    }

    public class Array2 {

        public static void printArray(int[][]a){
            for(int i=0;i<a.length;i++){
                for(int j=0; j<a[0].length;j++){
                    System.out.print(a[i][j]+" ");
                }
                System.out.println();
            }
        }
        Array2.printArray(a);
    }
}

Array Code

Answer 1

Actually you have two different problems. The first one is that you are using a matrix not an array. The second one is that you are trying to call the method on the second class when it does not have the a variable defined for that.

Try the following:

import java.util.Scanner;

public class TestArray2 {
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);

        int [] a = new int[input];
        for(int i=0; i<a.length;i++){

            if(i%2 == 0){
                a[i] = 0;
            } else {
                a[i] = 1;
            }
        }
        input.close();

        printArray(a);
    }

    public static void printArray(int[]a){
        for(int i=0;i<a.length;i++){
            System.out.print(a[i]+" ");
        }
        System.out.println();
    }
}

Answer 2

This should work, I skipped the second class

public class TestArray2 {
  public static void main(String[] args){

    int [][] a = new int[5][5];
    for(int i=0; i<a.length;i++){

        for(int j=0;j<a[i].length;j++){
            int x = j;
        if(x%2 == 0){
            a[i][j] = 0;
        }
        else  {
            a[i][j] = 1;
        }
    }

    }
    printArray(a);
  }
  public static void printArray(int[][] a) {
    for (int i = 0; i < a.length; i++) {
        for (int j = 0; j < a[i].length; j++) {
            System.out.print(a[i][j] + " ");
        }
        System.out.println();
    }
  }

}