Is pass-by-reference default?

Simple answer: Yes it is true. All values are passed by value unless specifically stated as a ref or out parameter. But you need to remember that a reference variable, i.e. a non-value-type variable such as an object, is already a reference.

What happens when an argument is passed by reference?

Pass-by-reference means to pass the reference of an argument in the calling function to the corresponding formal parameter of the called function. Use pass-by-reference if you want to modify the argument value in the calling function. Otherwise, use pass-by-value to pass arguments.

Is C++ default pass by value or reference?

Is C++ pass by value or pass by reference? C++ has both pass-by-value (when a function parameter or return type is not a reference type, e.g. int or std::string or void*) and pass-by-reference (when a function parameter or return type is a reference type, such as int& or const std::string& or void*&).

How is a default argument declared?

A default argument is a value provided in a function declaration that is automatically assigned by the compiler if the caller of the function doesn’t provide a value for the argument with a default value. When Function overloading is done along with default values.

How is the argument passed in pass by reference?

In pass by reference, a reference to the original argument is passed to the subroutine. As the argument within a subroutine is pointing to an original argument, any changes to the argument within subroutine will be visible outside. To indicate argument pass by reference, the argument declaration is preceded by keyword ref.

When to use const reference or pass 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. Because a copy of the argument is not made, pass by reference is fast, even when used with large structs or classes.

How do you pass a variable by reference?

To pass a variable by reference, we simply declare the function parameters as references rather than as normal variables: When the function is called, ref will become a reference to the argument. Since a reference to a variable is treated exactly the same as the variable itself, any changes made to the reference are passed through to the argument!

What are the local parameters in pass by reference?

Pass By Reference The local parameters are references to the storage locations of the original arguments passed in. Changes to these variables in the function willaffect the originals No copy is made, so overhead of copying (time, storage) is saved constReference Parameters: The keyword constcan be used on reference parameters.