Is it better to pass by reference or pointer?

Pass-by-references is more efficient than pass-by-value, because it does not copy the arguments. The formal parameter is an alias for the argument. Use pass-by-pointer if NULL is a valid parameter value or if you want to reassign the pointer. Otherwise, use constant or non-constant references to pass arguments.

Which is more efficient pass by value or pass by reference?

As a rule of thumb, passing by reference or pointer is typically faster than passing by value, if the amount of data passed by value is larger than the size of a pointer.

Why is it usually better to pass objects by reference than by value?

The reason is simple: if you passed by value, a copy of the object had to be made and, except for very small objects, this is always more expensive than passing a reference. With C++11, we have gained move semantics.

Is const reference faster?

Concerning objects (especially strings), call by reference is faster than call-by-value because the function call does not need to create a copy of the original object. Using const, one can also ensure that the reference is not abused.

What is the main advantage of passing arguments by reference?

Advantages of passing by reference: References allow a function to change the value of the argument, which is sometimes useful. Otherwise, const references can be used to guarantee the function won’t change the argument.

What is the difference between pass by value and pass by reference in C?

Pass by value refers to a mechanism of copying the function parameter value to another variable while the pass by reference refers to a mechanism of passing the actual parameters to the function.

What are the main advantages of passing arguments by reference?

Advantages of passing by reference:

• References allow a function to change the value of the argument, which is sometimes useful.
• Because a copy of the argument is not made, pass by reference is fast, even when used with large structs or classes.

Should I always pass by const reference?

It’s wrong. Passing the arguments of basic types (int, float, char….) is more effecient than passing them by reference. const & is more effecient in passing the BIG OBJECT. Because the reference is a alias of a object in essential, the compiler need to handle more information.

What is constant reference?

A constant reference is really a reference to a constant. The use of const in a declaration of a reference (argument) means that we do not want to change the referenced object.