#0072

Bank Account Class

EasyPython18 min15 XP

Problem

Implement BankAccount with balance, deposit(amount), and withdraw(amount). Deposit and withdraw should reject negative amounts with ValueError. withdraw should return False if funds are insufficient; otherwise update balance and return True.

Why This Matters

OOP interviews often test whether you understand instance state, validation, and method behavior more than inheritance trivia.

Function Signature

class BankAccount:

Examples

Example 1

Inputacct = BankAccount(100); acct.deposit(25); acct.withdraw(40)

OutputTrue and balance 85

The instance keeps its own balance as methods change state.

Constraints

Use instance attribute self.balance.
Reject negative amounts.
Do not allow overdraft.

CodePython

class BankAccount:
    def __init__(self, balance=0):
        self.balance = balance

    def deposit(self, amount):
        pass

    def withdraw(self, amount):
        pass

class BankAccount:
    def __init__(self, balance=0):
        self.balance = balance

    def deposit(self, amount):
        pass

    def withdraw(self, amount):
        pass

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Deposit and withdraw

Inputstart 100, deposit 25, withdraw 40

Expectedbalance 85

Both methods update the same account instance.

Insufficient funds

Inputstart 10, withdraw 50

ExpectedFalse and balance 10

Failed withdrawal should not change balance.

Hidden Test Categories

default balancenegative depositnegative withdrawal