everyutil/number/digitalRoot.js

A comprehensive library of lightweight, reusable utility functions for JavaScript and TypeScript, designed to streamline common programming tasks such as string manipulation, array processing, date handling, and more.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.digitalRoot = void 0;
/**
 * Calculates the digital root of a number (sum of digits until a single digit).
 * For example, digitalRoot(942) returns 6.
 * @author @dailker
 * @param {number} n - The number to process.
 * @returns {number} The digital root.
 */
function digitalRoot(n) {
    while (n >= 10) {
        n = n.toString().split('').reduce((a, b) => a + +b, 0);
    }
    return n;
}
exports.digitalRoot = digitalRoot;