Common types of C++ function return value types

C function return types include: void (no return value), basic types (integers, floating point numbers, characters and Boolean values), pointers, references, classes and structures. When choosing, consider functionality, efficiency, and interface. For example, the factorial function that calculates factorials returns an integer type to meet functional requirements and avoid extra operations.

Common types of C function return value types

Introduction

C functions can return various types of Values, including primitive types, classes, and structures. Choosing the appropriate return value type is crucial, as it determines the form and content of the data returned by the function.

Common types

The most common return value types of C functions include:

• void: Indicates that the function does not Return any value.
• Basic types: integers, floating point numbers, characters and Boolean values.
• Pointer: Points to the memory address of other data.
• Reference: Alias ​​pointing to other data.
• Classes and structures: Custom data types.

Choose the appropriate type

When choosing a return value type, you should consider the following factors:

• Function: The purpose of the function determines the data type it should return.
• Efficiency: Returning complex objects may require memory allocation and additional operations, which affects performance.
• Interface: The caller of a function expects to receive a return value of a specific type.

Practical case: Calculating factorial

Write a function to calculate the factorial of an integer.

int factorial(int n) {
  if (n == 0) {
    return 1;
  }

  return n * factorial(n - 1);
}

int main() {
  int number = 5;
  int result = factorial(number);
  cout << "The factorial of " << number << " is: " << result << endl;

  return 0;
}

In this example, the factorial function returns an integer (factorial). Since factorial is a non-negative integer, using the int data type is appropriate. The function calculates the factorial recursively, and if no value is returned, processing cannot continue.

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