C++ Default Arguments

In C++, default arguments allow functions to have default values for parameters. If a caller does not provide a value, the default is used.

1. Default Argument Syntax

Default values are specified in the function declaration or definition.

return_type function_name(data_type parameter = default_value) {
    // function body
}

2. Default Argument Example

This example demonstrates a function with default arguments.

#include <iostream>
using namespace std;

void greet(string name = "Guest") {
    cout << "Hello, " << name << "!" << endl;
}

int main() {
    greet(); // Uses default value
    greet("Alice"); // Overrides default value
    return 0;
}

3. Common Mistakes

Providing default arguments in both declaration and definition can cause errors. Always specify defaults in the declaration or in the definition if no declaration exists.

Conclusion

C++ default arguments simplify function calls by providing optional parameter values. They improve code readability and reduce overloads for similar functions.