Matrices: Intro

We could implement a matrix in Java as a two-dimensional (2D) array:

int[][] matrix = new int[n][m];

This matrix has

n

rows and

m

columns. To populate it with elements, we'll use a nested

for

loop:

for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
        matrix[i][j] = i + j;  // just an example

Example: 14. If we set

n = m = 3

and use the above code, we will get the matrix: $\begin{bmatrix} 0 & 1 & 2 \\ 1 & 2 & 3 \\ 2 & 3 & 4 \end{bmatrix}$.