What is a reference parameter C++?

When a reference parameter is used, the address (not the value) of an argument is automatically passed to the function. Within a function, operations on the reference parameters are automatically dereferenced. A reference parameter is declared by preceding the parameter name in the function’s declaration with an &.

How do you write a reference parameter in C++?

To indicate a reference parameter, an ampersand (&) is written in the function prototype and header after the parameter type name. For example, void assign(int& to, int from) { to = from; // Will change the actual parameter in the call. }

What is reference variable in C++ with example?

Reference variable is an alternate name of already existing variable. It cannot be changed to refer another variable and should be initialized at the time of declaration and cannot be NULL. The operator ‘&’ is used to declare reference variable.

What is a reference parameter in programming?

A reference parameter is an alias for its corresponding argument in a function call. To indicate that a function parameter is passed by reference, simply follow the parameter’s type in the function prototype by an ampersand (&); use the same convention when listing the parameter’s type in the function header.

How do you pass a string by reference in C++?

Your code works as expected. &filename returns the memory address of (aka a pointer to) filename , but startup(std::string& name) wants a reference, not a pointer. References in C++ are simply passed with the normal “pass-by-value” syntax: startup(filename) takes filename by reference.

Why reference variables are used in C++?

The main use of references is acting as function formal parameters to support pass-by-reference. In an reference variable is passed into a function, the function works on the original copy (instead of a clone copy in pass-by-value). Changes inside the function are reflected outside the function.

Which of the following is an example of a reference variable declaration?

Answer: String name; 1601 students attemted this question.

What is the difference between value parameter and reference parameter?

Changes to a value parameter are not visible to the caller (also called “pass by value”). Changes to a reference parameter are visible to the caller (“pass by reference”).