input: Write a function to populate an array with random numbers from 1 to 100 given the length of the array. The function should return the populated array.
  assert populateArray(5)
  assert populateArray(0)==[]
  assert len(populateArray(10))==10
output: import random
  
  def populateArray(length):
      return [random.randint(1, 100) for _ in range(length)]