Javascript で Python の random.sample みたいなのを書いてみるメモ

var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43];
var result_numbers;

// function random_sample(population, k) {
//   var numbers = [];
//   for (var num = 1; num <= k; num++) {
//     var pickup_num = Math.floor(Math.random() * population.length);
//     numbers.push(population.splice(pickup_num, 1)[0]);
//   }
//   return numbers;
// }
// 修正v0.2
function random_sample(population, k) {
  var num,
      begin,
      temp_arr = population.slice(0),
      numbers = [];
  for (num = 1; num <= k; num++) {
    begin = Math.floor(Math.random() * temp_arr.length);
    numbers.push(temp_arr.splice(begin, 1)[0]);
  }
  return numbers;
}

result_numbers = random_sample(numbers, 6);
console.log(result_numbers.sort(function(a, b) {
    return a - b;
  }));

// ex
//-> [ 3, 5, 6, 17, 23, 41 ]

参考サイト

• 9.6. random — 擬似乱数を生成する — Python 2.7ja1 documentation