# Find determinant of a matrix in Java Programming

In this section, you will learn how to determine the determinant of 2x2 matrix.

# Find determinant of a matrix in Java Programming

A determinant is a real number associated with every square matrix or, you can say it is a rectangular array of numbers where the number of rows and columns are equal.It is a scale factor for measure when the matrix is regarded as a linear transformation. Here we are going to find the determinant of 2x2 matrix.

In 2×2 matrix,
a[0][0] a[0][1]
a[1][0] a[1][1]
determinant = a[0][0] * a[1][1] - a[0][1] * a[1][0];

Here is the code:

```public class Determinant {
public int determinant(int[][] arr) {
int result = 0;
if (arr.length == 1) {
result = arr[0][0];
return result;
}
if (arr.length == 2) {
result = arr[0][0] * arr[1][1] - arr[0][1] * arr[1][0];
return result;
}
for (int i = 0; i < arr[0].length; i++) {
int temp[][] = new int[arr.length - 1][arr[0].length - 1];

for (int j = 1; j < arr.length; j++) {
for (int k = 0; k < arr[0].length; k++) {

if (k < i) {
temp[j - 1][k] = arr[j][k];
} else if (k > i) {
temp[j - 1][k - 1] = arr[j][k];
}
}
}
result += arr[0][i] * Math.pow(-1, (int) i) * determinant(temp);
}
return result;
}

public static void main(String[] args) {
int array[][] = { { 5, 6 }, { 8, 9 } };
Determinant d = new Determinant();
int result = d.determinant(array);
System.out.println(result);
}
}

```