C Tutorial

💻 Return Types in C

In C, functions can return a value to the caller. The return type specifies what type of data the function will return, such as int, float, or void. Functions may also return nothing, which is represented by the void return type.

🔄 Syntax of Return Types

The syntax for declaring a return type is placed before the function name. It indicates the data type of the value the function will return.

return_type function_name() {
    // Function body
    return value; // Return statement with the appropriate data type
}
  

Here, return_type specifies the data type, and value is the value the function returns to the caller.

🔧 Example 1: Returning an Integer

#include 

// Function that returns an integer
int add(int a, int b) {
    return a + b; // Returning the sum of a and b
}

int main() {
    int sum = add(5, 3); // Storing the returned value
    printf("Sum: %d\n", sum); // Output will be 8
    return 0;
}
  

🔧 Example 2: Returning a Float

#include 

// Function that returns a float
float average(float x, float y) {
    return (x + y) / 2; // Returning the average of x and y
}

int main() {
    float avg = average(5.0, 3.0); // Storing the returned value
    printf("Average: %.2f\n", avg); // Output will be 4.00
    return 0;
}
  

🔧 Example 3: Returning Nothing with void

#include 

// Function that doesn't return a value
void displayMessage() {
    printf("Hello, world!\n"); // Prints a message
}

int main() {
    displayMessage(); // Calling the function without expecting a return value
    return 0;
}
  

📌 Key Points to Remember

• The return type must match the type of value the function returns (e.g., int, float, or void).
• If a function has a non-void return type, it must return a value of that type using the return keyword.
• If the function's return type is void, it does not return any value, and the return statement is optional (though you can use it to exit early from the function).
• Functions that return values can be used in expressions or assigned to variables.

🔧 Example 4: Returning a String (Character Array)

#include 

// Function that returns a string (character array)
char* greet() {
    return "Hello, C Programmer!";
}

int main() {
    printf("%s\n", greet()); // Calling the function and printing the returned string
    return 0;
}
  

📝 Try It Yourself!

❌ Common Mistakes

• 🚫 Forgetting to use the return keyword when the function's return type is non-void.
• 🚫 Confusing the return type with the argument types. Ensure the return type matches the value you return.
• 🚫 Returning a value of the wrong type. For example, trying to return an int from a function declared to return float.