Google Spreadsheet - カスタム関数 RANDCHOICE

数式でランダムに選択する方法のメモ

• リストから要素をランダムで選ぶ =CHOOSE(RANDBETWEEN(1, 4), "A", "B", "C", "D")
• 範囲が対象の場合 =INDEX(A:A, RANDBETWEEN(1, 4))
• カスタム関数で =RANDCHOICE("A", "B", "C", "D")

/**
 * picking a random item from a list
 *
 * @param {"A", "B", "C"} items
 * @return one of choosed element
 * @customfunction
 */
function RANDCHOICE() {
  var xs = Array.prototype.slice.call(arguments);
  return xs[Math.floor(Math.random() * xs.length)];
}

参考URL

• Picking a random item from an array
• Did you know? (Custom Functions in Google Apps Script)
• Automatically generate documentation for your google apps script libraries