[Solved] Identify the bug in this order state machine method that allows invalid state transitions:def deliver(self): if self.state == 'Shipped' or 'Out for Delivery': self.state = 'Delivered' else:... | LLD

LLD - Design — Online Shopping Cart

Identify the bug in this order state machine method that allows invalid state transitions:

def deliver(self):
    if self.state == 'Shipped' or 'Out for Delivery':
        self.state = 'Delivered'
    else:
        raise Exception('Invalid transition');

AThe method should use 'and' instead of 'or'

BThe method does not change the state

CThe exception message is missing

DThe condition always evaluates to True due to incorrect or usage

Step-by-Step Solution

Solution:

Step 1: Analyze the condition logic
The condition uses 'if self.state == 'Shipped' or 'Out for Delivery'', which always evaluates True because non-empty strings are truthy.
Step 2: Correct the condition
It should be 'if self.state == 'Shipped' or self.state == 'Out for Delivery'' to check both states properly.
Final Answer:
The condition always evaluates to True due to incorrect or usage -> Option D
Quick Check:
Incorrect or condition causes always True [OK]

Quick Trick: Check boolean conditions carefully for correct comparisons [OK]

Common Mistakes:

Using 'or' with string literals incorrectly
Forgetting to compare both sides explicitly
Assuming condition works as intended

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More LLD Quizzes

Identify the bug in this order state machine method that allows invalid state transitions:

Step 1: Analyze the condition logic

Step 2: Correct the condition

Final Answer:

Quick Check:

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