The role of reference parameters in C++ functions

C Reference parameters allow a function to directly modify the variable at the calling function without creating a copy. Functions include: modifying actual parameters and providing direct access to original variables. Improve efficiency, avoid creating copies, and reduce memory overhead and time complexity. Avoid accidental modifications. Using reference parameters for input parameters prevents functions from accidentally modifying variables at the calling function.

The role of reference parameters of C function

Introduction

The reference parameters are A powerful tool in C that allows a function to directly modify the variable at the calling function instead of creating a local copy. This is especially useful in situations where large data structures need to be passed efficiently or where actual parameters need to be modified.

Syntax

Reference parameters are represented in function definitions using the & notation.

void myFunction(int &x);

Variables passed to reference parameters must be called using the & notation.

int main() {
  int y = 5;
  myFunction(y);
  // y 现在为 10
  return 0;
}

Function

• #Modify the actual parameters: The reference parameters provide the function with direct access to the variables at the calling function, so Functions can modify original variables.
• Improve efficiency: Unlike pass-by-value parameters, reference parameters do not create a copy of the original variable, which reduces memory overhead and time complexity, especially when passing large data structures.
• Avoid accidental modifications: Using reference parameters for input parameters prevents functions from accidentally modifying variables at the calling function.

Practical case

Consider a function that exchanges two integers:

void swap(int &a, int &b) {
  int temp = a;
  a = b;
  b = temp;
}

Call this function:

int x = 5, y = 10;
swap(x, y);
// x 现在为 10，y 为 5

Conclusion

Reference parameters are a powerful tool in C that can be used to improve function efficiency, directly modify actual parameters, and prevent accidental modifications.

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