Can you give me examples of refactoring in different programming languages?

Can you give me examples of refactoring in different programming languages?

Sure! Refactoring is the process of restructuring existing computer code without changing its external behavior. Here are examples in a few languages:

1. Python: Changing a function to use list comprehensions for better readability.
2. Java: Extracting a method to reduce code duplication.
3. JavaScript: Using arrow functions to simplify function expressions.
4. C#: Implementing the Strategy pattern to improve code flexibility.

Can you elaborate on the Python example?

Absolutely! In Python, consider this initial function:

def get_even_numbers(numbers):
    even_numbers = []
    for number in numbers:
        if number % 2 == 0:
            even_numbers.append(number)
    return even_numbers

After refactoring, it can be simplified using a list comprehension:

def get_even_numbers(numbers):
    return [number for number in numbers if number % 2 == 0]

What about the Java example?

In Java, let's say you have this code that calculates the area of different shapes:

public double calculateArea(String shape, double dimension) {
    if (shape.equals("circle")) {
        return Math.PI * dimension * dimension;
    } else if (shape.equals("square")) {
        return dimension * dimension;
    }
    return 0;
}

You can refactor it by extracting methods for each shape:

public double calculateArea(String shape, double dimension) {
    switch (shape) {
        case "circle": return calculateCircleArea(dimension);
        case "square": return calculateSquareArea(dimension);
        default: return 0;
    }
}

private double calculateCircleArea(double radius) {
    return Math.PI * radius * radius;
}

private double calculateSquareArea(double side) {
    return side * side;
}