# Java Program to Check if a Given Matrix is an Identity Matrix

# Overview

In this blog, we will enroll in creating a Java program that checks if a given matrix is a identity matrix or not. It is essential to check if the given matrix is a square matrix or not. If it is satisfied, then the condition for checking the identity matrix can be executed.

# What is identity matrix?

The formal definition of an identity matrix states that it is a **square matrix** in which all the elements of the principal diagonal are ones and all other elements are zeros.

The identity matrix is denoted by **“I”**. Its is that when a given matrix is multiplied with identity matrix, it leaves the given matrix unchanged.

# Algorithm

- Declare and define a matrix of appropriate elements.
- Find the number of rows and number of columns in the matrix.
- If the number of rows is not equal to the number of columns, then print that it is not a square matrix.
- Else, loop through each elements of the matrix and assign the flag value to be true initially.
- Check if the diagonal elements are ones. If not, assign the flag value to be false and break the loop.
- Check if the elements other than the diagonal elements are zeros. If not, assign the flag value to be false and break the loop.
- If all the diagonal elements are ones and all other elements are zeros, then the flag value remains true. Print that the matrix is an identity matrix.
- If the flag value becomes false, print that the matrix is not an identity matrix.

`if(rowLength != columnlength) `

System.out.println("OOPS! The matrix is not a square matrix");

else {

for(int i = 0; i < rowLength; i++) {

for(int j = 0; j < columnLength; j++) {

if((i == j) && (matrix[i][j] != 1)) {

flag = false;

break;

}

if(((i != j) && (matrix[i][j] != 0)) {

flag = false;

break;

}

}

}

}

# Source Code

Here is the complete Java program that checks if a given matrix is an identity matrix or not:

# Output

Are you looking to master coding and crack top company interviews? Go ahead and try GUVI’s Pro Subscription to help you with everything needed to build a strong Technical Career.

Know more about GUVI:

Also, download GUVI’s app to learn the latest IT skills in vernacular languages.