Find the logical error in this balance update pseudocode:

medium📝 Analysis Q6 of 15

LLD - Design — Splitwise (Expense Sharing)

balance = 200
for txn in transactions:
  balance = txn

ALoop does not iterate over transactions

BBalance is overwritten instead of updated

CInitial balance is set incorrectly

DTransactions list is empty

Step-by-Step Solution

Solution:

Step 1: Review code logic
The loop assigns balance to the current transaction value each iteration.
Step 2: Identify issue
This overwrites balance instead of accumulating transaction amounts.
Step 3: Correct approach
Use balance += txn to add each transaction to balance.
Final Answer:
Balance is overwritten instead of updated -> Option B
Quick Check:
Assignment '=' replaces value; use '+=' to accumulate [OK]

Quick Trick: Use '+=' to add, not '=' to overwrite balance [OK]

Common Mistakes:

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