/**
 * 获取指定随机数
 * randomNumer(最大值，最小值，保留几位小数)
 */
export function randomNumer(maxNum, minNum, decimalNum) {
  // 获取指定范围内的随机数, decimalNum指小数保留多少位
  var max = 0,
      min = 0;
  minNum <= maxNum ? (min = minNum, max = maxNum) : (min = maxNum, max = minNum);
  switch (arguments.length) {
    case 1:
        return Math.floor(Math.random() * (max + 1));
        break;
    case 2:
        return Math.floor(Math.random() * (max - min + 1) + min);
        break;
    case 3:
        return (Math.random() * (max - min) + min).toFixed(decimalNum);
        break;
    default:
        return Math.random();
        break;
  }
}