# Matrix Multiplication in Java

Shubham Vora Nov 15, 2022

In this article, we will learn to multiply the two matrices in Java.

## Multiply Two Matrices In Java

We are using the multiplication and addition operators to multiply two matrices. Users should follow the below steps to multiply two matrices.

• ##### Use the nested loop to multiply each row of the 1st matrix with each column of the 2nd matrix. Store the sum of it in the output matrix.

Example Code:

``````class Test{
public static void main(String[] args) {
// create matrices to multiply
int[][] a = {{11,2,3},{1,2,13},{1,12,3}};
int[][] b ={{14,5,6},{4,5,6},{4,5,6}};
// initialize array with zeros to store the result
int[][] c = {{0,0,0},{0,0,0},{0,0,0}};
// multiply A and B matrix
for (int i = 0; i < a.length; ++i) {
for (int j = 0; j < b.length; ++j) {
// Initialize with 0, if not already
c[i][j] = 0;
// Multiply the ith row of A matrix and the jth column of B matrix and store its sum to C matrix as a result
for (int k = 0; k < a.length; ++k) {
c[i][j] += a[i][k] * b[k][j];
}
}
}
// Print the resultant matrix
System.out.println("Matrix Multiplication of A and B is  ");
for (int i = 0; i < a.length; ++i) {
for (int j = 0; j < b.length; ++j) {
System.out.print(c[i][j]);
System.out.print("\t");
}
System.out.println("\n");
}
}
}
``````

Output:

``````Matrix Multiplication of A and B is
174	80	96

74	80	96

74	80	96
``````

### Time Complexity of the Matrix Multiplication

The time complexity for the matrix multiplication is `O(M^3)`, as we are using 3 nested loops.

### Space Complexity of the Matrix Multiplication

The space complexity for the matrix multiplication algorithm is `O(M^2)`.

Author: Shubham Vora

Shubham is a software developer interested in learning and writing about various technologies. He loves to help people by sharing vast knowledge about modern technologies via different platforms such as the DelftStack.com website.