Learn Encapsulation by Building a Projectile Trajectory Calculator - Step 4

Python
1

Tell us what’s happening:

The console just says there is an issue in your code but the preview isn’t showing any error. So am I doing wrong here

Your code so far

import math

GRAVITATIONAL_ACCELERATION = 9.81
PROJECTILE = "∙"
x_axis_tick = "T"
y_axis_tick = "⊣"

class Projectile:
    __slots__ = ('__speed', '__height', '__angle')

    def __init__(self, speed, height, angle):
        self.__speed = speed
        self.__height = height
        self.__angle = math.radians(angle)
        

# User Editable Region

    def __calculate_displacement(self):
        v=self.speed
        a=self.angle
        g=GRAVITATIONAL_ACCELERATION
        h=self.height 
        return (v * math.cos(a) * (v * math.sin(a) + math.sqrt(v**2 * math.sin(a)**2 + 2 * g * h))) / g

# User Editable Region

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Challenge Information:

Learn Encapsulation by Building a Projectile Trajectory Calculator - Step 4

2

the error is hidden in the browser console, AttributeError: 'Projectile' object has no attribute 'speed'

3

oh my bad I just didn’t use the underscores in defining variables.

thank you