js 隨機獲取數組里面指定的值

getRandomArrayElements(arr, count) {
      var shuffled = arr.slice(0), i = arr.length, min = i - count, temp, index;
      while (i-- > min) {
          index = Math.floor((i + 1) * Math.random());
          temp = shuffled[index];
          shuffled[index] = shuffled[i];
          shuffled[i] = temp;
      }
      // var items = ['1','2','4','5','6','7','8','9','10'];
      // console.log( getRandomArrayElements(items, 4) );
      return shuffled.slice(min);
    },