mcsee

<?

  $sourceFile = 'C:\temp\source.txt';
  $destination = 'C:\temp\destination :txt';
  // The filename is simplified
  // and might come from a programatic construction

  $copyWasSuccessful = copy($sourceFile, $destination);  
  if (!$copyWasSuccessful || !$file_exists($destination)) {
    // Dont trust the function result. Handle the postcondtion error

mcsee

<?

  $sourceFile = 'C:\temp\source.txt';
  $destination = 'C:\temp\destination.txt';
  $copyWasSuccessful = copy($sourceFile, $destination); // true
  $destinationFileExists = file_exists($destination); // true
  
  $sourceFile = 'C:\temp\source.txt';
  $destination = 'C:\temp\destination :txt';
  // The filename is simplified 

mcsee

const pets = '😺🐶😺';

const justDogs = pets.replaceAll('😺', '🐩');
// Or
const justDogs = pets.replace(/😺/g, '');

const catsArePresent = justDogs.includes('😺');
// returns false

mcsee

const pets = '😺🐶😺';
const justDogs = pets.replace('😺', '🐩');

const catsArePresent = justDogs.includes('😺');
// returns true

mcsee

class CreditCard {
  private String number;
  private MonthOfYear expiryDate;
  // expiryDate is the role
  // MonthOfYear is the type
}

class MonthOfYear {
  private Month month;  
  private Year year;

mcsee

public class CreditCard {
    private String cardNumber;
    private int expiryMonth;
    private int expiryYear;

    public CreditCard(String cardNumber, int expiryMonth, int expiryYear) {
        this.cardNumber = cardNumber;
        this.expiryMonth = expiryMonth;
        this.expiryYear = expiryYear;
        // No validations on number ranges?

mcsee

import java.util.Date;

public class CreditCard {
    private String cardNumber;
    private Date expiryDate;

    public CreditCard(String cardNumber, Date expiryDate) {
        // Not a complete date
        this.cardNumber = cardNumber;
        this.expiryDate = expiryDate;

mcsee

def calculate(mathOperand, firstArgument, secondArgument):
    if mathOperand == '+':
        return firstArgument + secondArgument
    elif mathOperand == '-':
        return firstArgument - secondArgument
    elif mathOperand == '*':
        return firstArgument * secondArgument
    elif mathOperand == '/':
        if secondArgument != 0:
            return firstArgument / secondArgument

mcsee

def calculate(mathOperand, firstArgument, secondArgument):
    return eval(f'{firstArgument} {mathOperand} {secondArgument}')

# Sample usage to multiply two numbers
result = calculate('*', 4, 6)

# Injection to remove all files
calculate('', "__import__('os').system('rm -rf *')",''))

mcsee

VALID_COLUMNS = ['name', 'gender', 'email']

def process_API_information(data):
    invalid_columns = [
        column for column in data.keys() if column not in VALID_COLUMNS
    ]
    
    if invalid_columns:
        raise ValueError(
            f"Invalid columns detected: {', '.join(invalid_columns)}"