JavaScript: Sum of the main diagonal elements of a square matrix

Last update on December 02 2022 12:38:49 (UTC/GMT +8 hours)

JavaScript Math: Exercise-85 with Solution

Write a JavaScript program to compute the sum of the main diagonal elements of a square matrix.

In mathematics, a matrix (plural matrices) is a rectangular array or table of numbers, symbols, or expressions, arranged in rows and columns, which is used to represent a mathematical object or a property of such an object.
An m × n matrix: the m rows are horizontal and the n columns are vertical
JavaScript Math: Sum of the main diagonal elements of a square matrix.
In mathematics, a square matrix is a matrix with the same number of rows and columns. An n-by-n matrix is known as a square matrix of order n. Any two square matrices of the same order can be added and multiplied.
Example:

Test Data:
([ [1, 2, 3], [4, 5, 6], [7, 8, 9] ]) -> 15
( [ [-1, -2], [-4, -5] ]) -> -6

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript program to Sum of the main diagonal elements of a square matrix</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function test(nums) {
    return nums.reduce((x,y,i)=>x+y[i],0);
}
nums = [
        [1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]
       ]
console.log("Sum of the main diagonal elements of the said square matrix: "+test(nums));
nums = [
        [-1, -2],
        [-4, -5]
       ]
console.log("Sum of the main diagonal elements of the said square matrix: "+test(nums));

Sample Output:

Sum of the main diagonal elements of the said square matrix: 15
Sum of the main diagonal elements of the said square matrix: -6

Flowchart:

$JavaScript: Sum of the main diagonal elements of a square matrix.$

Live Demo:

See the Pen javascript-math-exercise-85 by w3resource (@w3resource) on CodePen.

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