Do function parameter variables always require a & or * operator?

by

Those * and & in your code are neither dereference nor address-of operators. Both, * and & can have different meanings. Here they are part of the type:

int x;      // declares an int
int* p;     // declares a pointer to int
int& r = x; // declares a reference to int

The address-of and dereference operators come into play for example when you assign something to the above variables:

p = &x; // here & is address-of operator
x = *p; // here * is dereference operator

int someFunction(std::vector<int>& nums) {
     //do stuff 
}

In this context the & is being used to declare that the address of the nums variable is being used rather than the value.

No. Here the & means that nums is passed as reference.

If this signature is changed to the below, the value is being used
instead.

int someFunction(std::vector<int>* nums) {
     //do stuff 
}

No. Here nums is passed as pointer.

Only this is pass-by-value:

int someFunction(std::vector<int> nums) {
     //do stuff 
}

More Related Contents:

  1. segmentation fault in an sorted linked list program for Homework [closed]
  2. How to execute a c# exe from a c++ program
  3. Store derived class objects in base class variables
  4. Why does rand() yield the same sequence of numbers on every run?
  5. Why don’t I get a segmentation fault when I write beyond the end of an array?
  6. cudaMemcpy segmentation fault
  7. Same random numbers every loop iteration
  8. How do I print the elements of a C++ vector in GDB?
  9. Getting the actual length of a UTF-8 encoded std::string?
  10. std::string::c_str() and temporaries
  11. How to use clock() in C++
  12. Namespaces in C
  13. declare template friend function of template class
  14. Deleting specific line from file
  15. “Undefined symbols” linker error with simple template class
  16. Impact of cubic and catmull splines on image
  17. Spirit-Qi: How can I write a nonterminal parser?
  18. What’s the fastest way to pack 32 0/1 values into the bits of a single 32-bit variable?
  19. Which types on a 64-bit computer are naturally atomic in gnu C and gnu C++? — meaning they have atomic reads, and atomic writes
  20. Refreshing the auto complete (IntelliSense) database in Visual Studio
  21. Why can I access private variables in the copy constructor?
  22. What’s the difference between opening a file with ios::binary or ios::out or both?
  23. How to convert a command-line argument to int?
  24. What is different between join() and detach() for multi threading in C++?
  25. Does std::mutex create a fence?
  26. Should you overload swap in the std namespace?
  27. weak_ptr, make_shared and memory deallocation
  28. C++ Virtual function being hidden
  29. How is floating point conversion actually done in C++?(double to float or float to double)
  30. Questions regarding C++ non-POD unions

Leave a Comment