I am currently taking Java lessons, and the course is explaining two-dimensional arrays. The first method to declaring that type of variable would be to create a constant as arguments for how many rows and columns will be in my two-dimensional array. Then, I just used a nested for-loop to give random numbers to those particular rows, and columns.
The second method to declare AND initialize a two-dimensional array would be "int[][] nums" line below. I know that it has 3 rows. It's basically similar to putting a list in a bigger list, but how many columns are in the "nums" array? There may be a simple answer, but I am a little confused right now. Thank you for the assistance.
import java.util.Random; //Importing Class from Package
public class Chap15Part4
{
public static void main(String[] args)
{
final int rows = 5; //Constant
final int cols = 5; //Constant
int[][] numbers = new int[rows][cols]; //Declaring 2-D Array with constants as arguments
Random rand = new Random(System.currentTimeMillis()); //Seeding Random Number Generator
for(int r = 0; r < rows; ++r) //Nested for-loop to assign numbers to elements
for (int c = 0; c < cols; ++c)
numbers[r][c] = rand.nextInt(101);
int[][] nums = {{10,20,30,40}, {20,30,40,50}, {30,40,50,60}}; //Declaring & Initializing 2-D Array
}
}
There are four columns. The matrix will look like this, so you can count the columns easily: