Passing Vectors in C++: By Value or Reference?

When it comes to passing vectors in C++, there are two options: passing by value or passing by reference. The choice between the two depends on the specific needs of the program.

Passing by value means that a copy of the entire vector is made and passed as an argument to a function. This can be useful when the function needs to modify the vector without affecting the original one. However, passing by value can be inefficient and slow, especially if the vector is large.

On the other hand, passing by reference means that a reference to the original vector is passed as an argument to a function. This allows the function to modify the original vector directly, without creating a copy. Passing by reference is generally faster and more efficient than passing by value.

To pass a vector by reference in C++, the ampersand (&) symbol is used in the function parameter. For example:

void myFunction(vector<int>& myVector) {
    // Code to modify myVector directly
}

In conclusion, the decision to pass a vector by value or reference depends on the specific needs of the program. If the function only needs to read the vector, passing by value may be more appropriate. However, if the function needs to modify the vector, passing by reference is generally the better option.