# Java Program to Find Sum of Matrix Elements

In the previous article, we have discussed Java Program to Print 3*3 Matrix

In this article we are going to see how we can write a program to calculate the sum of matrix elements in JAVA language.

## Java Program to Find Sum of Matrix Elements

A 3*3 Matrix is having 3 rows and 3 columns where this 3*3 represents the dimension of the matrix. Means there are 3*3 i.e. total 9 elements in a 3*3 Matrix.

Let’s understand it in more simpler way.

                   | A00   A01   A02 |
Matrix A =  | A10   A11   A12 |
| A20   A21   A22 | 3*3
• Matrix A represents a 3*3 matrix.
• A‘ represents the matrix element
• Aij‘ represents the matrix element at it’s matrix position/index.
• i‘ represents the row index
• j‘ represents the column index
• Means A00=Aij  where i=0 and j=0A01=aij where i=0 and j=1 and like this.
• Here we have started row value from 0 and column value from 0.

Let’s see different ways to find sum of matrix elements.

### Method-1: Java Program to Find Sum of Matrix Elements By Static Initialization of Array Elements

Approach:

• Initialize and declare an array of size 3×3 with elements.
• Use two for loops to iterate the rows and columns and then add each element to the sum variable.
• Print the sum.

Program:

import java.util.Scanner;

public class Matrix
{
public static void main(String args[])
{
//Scanner class to take input
Scanner scan = new Scanner(System.in);

// Initializing the 3X3 matrix i.e. 2D array
int arr[][] = {{10,20,30},{40,50,60},{70,80,90}};
int row, col, sum = 0;

System.out.print("The matrix elements are : ");
// Loop to print the elements
for(row=0;row<3;row++)
{
// Used for formatting
System.out.print("\n");
for(col=0;col<3;col++)
{
System.out.print(arr[row][col]+" ");
}
}

// Loop to take the sum of elements
for(row=0;row<3;row++)
for(col=0;col<3;col++)
sum+=arr[row][col];

System.out.print("\nThe sum of all the matrix elements is : "+sum);
}
}

Output:

The matrix elements are :
10 20 30
40 50 60
70 80 90
The sum of all the matrix elements is : 450

### Method-2: Java Program to Find Sum of Matrix Elements By Dynamic Initialization of Array Elements

Approach:

• Initialize an array of size 3×3.
• Ask the user for input.
• Use two for loops to iterate the rows and columns and input the array elements.
• Similarly use two for loops to add each element and store in sum variable.
• Print the sum.

Program:

import java.util.Scanner;
public class matrix{
public static void main(String args[])
{
//Scanner class to take input
Scanner scan = new Scanner(System.in);

// Initializing the 3X3 matrix i.e. 2D array
int arr[][] = new int[3][3], sum = 0;

System.out.println("Enter the 3x3 matrix elements : ");
int row, col;
// Loop to take user input
for(row=0;row<3;row++)
for(col=0;col<3;col++)
arr[row][col] = scan.nextInt();

System.out.print("The matrix elements are : ");
// Loop to print the elements
for(row=0;row<3;row++)
{
// Used for formatting
System.out.print("\n");
for(col=0;col<3;col++)
{
System.out.print(arr[row][col]+" ");
}
}

System.out.print("\n");

// Loop to take the sum of elements
for(row=0;row<3;row++)
for(col=0;col<3;col++)
sum+=arr[row][col];

System.out.println("The sum of all the matrix elements is : "+sum);
}
}

Output:

Enter the 3x3 matrix elements : 1 2 3 4 5 6 7 8 9
The matrix elements are :
1 2 3
4 5 6
7 8 9
The sum of all the matrix elements is : 45

Have you mastered basic programming topics of java and looking forward to mastering advanced topics in a java programming language? Go with these ultimate Advanced java programs examples with output & achieve your goal in improving java coding skills.

Related Java Programs: