Search code examples
c++pointersreferencedereference

What are the differences between char** and char*& in CPP

For an assignment I came across this question.

What is the result of the statement following the definitions given below?

    char c='a';
    char *pc=&c;
    char *&rc=pc ;
    (*rc)++;

after printing all the different variables it shows that now variable c stores 'b'. I didn't understand why. Can anyone please explain?

Solution

  • Both char** (pointer-to-pointer) and char*& (reference-to-pointer) are second level abstractions of a value. (There's no pointer-to-reference type btw.)

    The differences are really the same as they are for regular pointers vs. references: nullable vs. non-nullable etc. See here for more: https://www.geeksforgeeks.org/pointers-vs-references-cpp/

    In your example, incrementing *rc does the same as would with using *pc. Note that you don't need a symbol for accessing a references value as you would with * when using a pointer.

    Just for fun: Try char** ppc = &pc. Can you tell what this does ?