What is the use of C++ function reference parameters?

Reference parameters improve performance, synchronize data and simplify code by sharing memory addresses: Improve performance: avoid copying actual parameter values ​​and improve execution efficiency. Data synchronization: Modifying reference parameters will be synchronized to the original variables. Simplify code: Eliminate the need to pass large objects or complex data.

#C The wonderful use of function reference parameters

Reference parameters are a mechanism in which actual parameters and formal parameters share the same memory address. In C, reference parameters are prefixed with a single & symbol.

Advantages:

• Performance improvement: Reference parameters avoid the cost of copying actual parameter values, thus improving the execution efficiency of the function .
• Data synchronization: Any modification to the reference parameters will be immediately reflected in the original variables passed in the calling function, ensuring data consistency.
• Simplified code: Reference parameters eliminate the need to pass large objects or complex data, making the code more concise and easier to read.

Practical case:

Suppose we have a function swap(), which exchanges two integers a and the value of b:

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

In this code, we use the reference parameters a and b. Reference can avoid copying the value of the actual parameter, thereby improving efficiency. Additionally, modifications within the function are immediately reflected in the original variables a and b in the calling function.

We can demonstrate swap() function in the following code:

int main() {
  int x = 5;
  int y = 10;

  swap(x, y);  // 交换 x 和 y 的值

  cout << "x: " << x << " y: " << y << endl;  // 输出：x: 10 y: 5
}

Note:

• Quote Parameters must be initialized, otherwise a compilation error will occur.
• Reference parameters cannot be reallocated, that is, they point to different memory addresses.

By rational use of reference parameters, we can improve the efficiency, data synchronization and code simplicity of C functions.

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