w3resource

JavaScript: Check whether a matrix is a diagonal matrix or not

JavaScript Basic: Exercise-115 with Solution

Write a JavaScript program to check whether a matrix is a diagonal matrix or not. In linear algebra, a diagonal matrix is a matrix in which the entries outside the main diagonal are all zero (the diagonal from the upper left to the lower right).

Example:
[1, 0, 0], [0, 2, 0], [0, 0, 3] ]) = true
[1, 0, 0], [0, 2, 3], [0, 0, 3] ]) = false

Pictorial Presentation:

JavaScript: Check whether a matrix is a diagonal matrix or not.

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title> Check whether a matrix is a diagonal matrix or not</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function is_diagonal_matrix(user_matrix) {
    for (var i = 0; i < user_matrix.length; i++) {
        for (var j = 0; j < user_matrix.length; j++) {
            if (i !== j && user_matrix[i][j] !== 0) 
              return false;
        }
    }
    return true;
}


console.log(is_diagonal_matrix([[1, 0, 0], [0, 2, 0], [0, 0, 3] ]));
console.log(is_diagonal_matrix([[1, 0, 0], [0, 2, 3], [0, 0, 3] ]));

Sample Output:

true
false

Flowchart:

Flowchart: JavaScript - Check whether a matrix is a diagonal matrix or not

ES6 Version:

function is_diagonal_matrix(user_matrix) {
    for (let i = 0; i < user_matrix.length; i++) {
        for (let j = 0; j < user_matrix.length; j++) {
            if (i !== j && user_matrix[i][j] !== 0) 
              return false;
        }
    }
    return true;
}


console.log(is_diagonal_matrix([[1, 0, 0], [0, 2, 0], [0, 0, 3] ]));
console.log(is_diagonal_matrix([[1, 0, 0], [0, 2, 3], [0, 0, 3] ]));

Live Demo:

See the Pen javascript-basic-exercise-115 by w3resource (@w3resource) on CodePen.


Contribute your code and comments through Disqus.

Previous: Write a JavaScript program to check whether a given string represents a correct sentence or not.
Next: Write a JavaScript program to find all the possible options to replace the hash in a string (Consists of digits and one hash (#)) with a digit to produce an integer divisible by 3.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

JavaScript: Tips of the Day

Parse an HTTP Cookie header string and return an object of all cookie name-value pairs

Example:

const parseCookie = str =>
  str
    .split(';')
    .map(v => v.split('='))
    .reduce((acc, v) => {
      acc[decodeURIComponent(v[0].trim())] = decodeURIComponent(v[1].trim());
      return acc;
    }, {});
console.log(parseCookie('foo=bar; equation=E%3Dmc%5E2')); // { foo: 'bar', equation: 'E=mc^2' } 

Output:

[object Object] {
  equation: "E=mc^2",
  foo: "bar"
} 

 





We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook