What are the benefits of reference parameters in C++?

Reference parameters are an efficient way to pass variables in C functions, allowing functions to directly access and modify external variables without creating copies. They can be used to improve performance, modify external variables, and avoid implicit conversions. Practical examples include functions to exchange two numbers and functions to obtain the length of a string.

The wonderful use of C reference parameters

Introduction
Reference parameters are a kind of function in C An efficient way to pass certain variable types in a function, which allows functions to directly access and modify external variables instead of creating copies. This is useful in a variety of scenarios, improving performance and simplicity.

Syntax
When declaring a reference parameter, add a & symbol before the parameter type. For example:

void myFunction(int &value);

Within a function, use the & notation to get the address of the reference variable.

void myFunction(int &value) {
  // 直接修改 value
  value *= 2;
}

Magic

1. Improve performance
Passing reference parameters avoids the overhead of creating copies when passing values, which is useful for large objects or complex data structures are particularly important.

2. Modify external variables
Reference parameters allow functions to modify external variables directly without returning the modified value.

3. Avoid implicit conversions
When passing values ​​of basic types, C will automatically convert them into references. Use reference parameters to explicitly specify the type passed and avoid unnecessary conversions.

Practical case

Function to exchange two numbers
The following function uses reference parameters to exchange the values ​​of two numbers:

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

Get the length function of a string
The following function uses reference parameters to get the length of a string:

int getLength(const string &s) {
  return s.size();
}

Conclusion
The reference parameters are C programming provides powerful capabilities. By directly manipulating external variables, they can significantly improve performance, simplicity, and enhance code readability.

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