human
90 degree rotation of array in 2D.
assistant
Here is a Python code to 90 degree rotation of an array in 2d

import numpy as np

def rotate_90(x):
    """Rotates the array by 90 degrees.

    :param x: The array to be rotated
    """
    return np.rot90(x, 1)

# Enter the array
x = np.array([[1, 2], [3, 4]])

# Calling the function
print((rotate_90(x)))

#Example Output
# [[2 4]
#  [1 3]]

#Remember to inspect code for bugs.