convert_fromArray.js

/**
 * Converts an array to a comma-separated string
 * @param {Array} arr - The input array
 * @returns {string | undefined} - The comma-separated string or undefined if the input is not an array
 * @example
 * const inputArray = ['a', 'b', 'c'];
 * const result = fromArray(inputArray); // 'a,b,c'
 */
export function fromArray (arr) {
  return Array.isArray(arr) ? arr.toString() : undefined
}