Functions in A++

Functions are reusable blocks of code that perform specific tasks. A++ provides a rich set of features for working with functions.

Function Basics

Function Declaration

// Basic function
#define yield_type function_name(parameter_type parameter) {
    // function body
    yield value;
}

// Example
#define int add(int a, int b) {
    yield a + b;
}

Function Types

// Nothing function (no return value)
#define nothing greet(string name) {
    print("Hello, " + name + "!");
}

// Function with return value
#define int multiply(int x, int y) {
    yield x * y;
}

// Function with multiple parameters
#define string formatName(string firstName, string lastName) {
    yield firstName + " " + lastName;
}

Advanced Function Features

Recursion

// Recursive factorial function
#define int factorial(int n) {
    if (n <= 1) {
        yield 1;
    }
    yield n * factorial(n - 1);
}
print("Factorial of 5: " + factorial(5)); //Ouput: factorial of 5: 120

Best Practices

1. Single Responsibility

// Bad: Function does too much
#define nothing processUser(User user) {
    validateUser(user);
    saveToDatabase(user);
    sendEmail(user);
}

// Good: Separate concerns
#define nothing  validateUser(User user) { ... }
#define nothing  saveUser(User user) { ... }
#define nothing  notifyUser(User user) { ... }

2. Descriptive Names

// Bad
#define nothing  p(string s) { ... }

// Good
#define nothing  printMessage(string message) { ... }

3. Parameter Validation

#define int calculateArea(int width, int height) {
    if (width <= 0 || height <= 0) {
        print("Dimensions must be positive");
        yield 0;
    }
    yield width * height;
}

4. Yield Early Pattern

#define boolean validateUser(User user) {
    if (!user.name) yield nope;
    if (!user.email) yield nope;
    if (user.age < 18) yield nope;
    yield yup;
}

Next Steps

• Learn about Classes and Objects
• Explore Error Handling
• Study Advanced Topics