What is the difference between functional programming and procedural programming?

Is functional programming process-oriented? Specific code examples are needed

In recent years, functional programming has become a hot topic in the field of software development. It is widely discussed and used by many developers. However, for developers who are used to procedural programming, the concept of functional programming can be somewhat confusing. They may wonder whether functional programming is a process-oriented programming style. In this article, we will explore the relationship between functional programming and procedural programming, and use concrete code examples to deepen our understanding.

The core idea of ​​functional programming is to regard the calculation process as a combination of a series of mathematical functions, rather than a series of states that are constantly modified. It emphasizes the purity and immutability of functions. In functional programming, functions have no side effects, that is, they do not change any external state. This pure function feature makes the code more readable, maintainable, and facilitates concurrent programming.

In contrast, process-oriented programming is a process-centered programming way of thinking. It decomposes complex problems into a series of steps and operations, and implements program functions by modifying shared states. Process-oriented programming emphasizes the relationship between process and data, and modification of state is the core of programming.

Let’s use a specific example to understand the difference between functional programming and process-oriented programming. Suppose we want to square the numbers in a list and return the squared list. First, we use a process-oriented approach to implement this function:

def square(numbers):
    results = []
    for num in numbers:
        results.append(num * num)
    return results

numbers = [1, 2, 3, 4, 5]
squared_numbers = square(numbers)
print(squared_numbers)  # [1, 4, 9, 16, 25]

In the above code, we iterate through each number in the list, square it, add it to a new list, and finally return result. This approach decomposes the calculation process into a series of steps and operations, and implements it by modifying a shared list.

If we use functional programming to implement this function, the code will look like this:

def square(num):
    return num * num

numbers = [1, 2, 3, 4, 5]
squared_numbers = list(map(square, numbers))
print(squared_numbers)  # [1, 4, 9, 16, 25]

In the above code, we define a pure function square, which accepts a number as input and returns the square of that number. We then use the map function to apply the square function to each number in the list and form the results into a new list. This method implements the calculation process by combining mathematical functions without modifying any external state.

It can be seen that functional programming and process-oriented programming have different ways of thinking and code structures when implementing the same functions. Functional programming emphasizes the purity and immutability of functions, and implements functions by treating the calculation process as a combination of a series of functions. Process-oriented programming takes the relationship between process and data as the core and implements functions by modifying the shared state.

To sum up, functional programming and process-oriented programming are two different programming methods. Functional programming implements functions through pure functions and immutability, allowing for better readability and maintainability. In terms of dealing with concurrent programming and large-scale system development, the advantages of functional programming are even more obvious.

In fact, there is no distinction between functional programming and process-oriented programming. It is about choosing the appropriate programming method in different scenarios. When solving complex problems, we can use these two programming methods in combination to give full play to their respective advantages and improve code quality and development efficiency.

The above is the detailed content of What is the difference between functional programming and procedural programming?. For more information, please follow other related articles on the PHP Chinese website!