获取两点之间距离

• 可能用处不大，就当认识Math.abs和Math.sqrt两个方法了

function getPointDistance (pointOne, pointTwo) {
  const minusX = Math.abs(pointOne[0] - pointTwo[0])

  const minusY = Math.abs(pointOne[1] - pointTwo[1])

  return Math.sqrt(minusX * minusX + minusY * minusY)
}