Question

In C++ (Microsoft Visual Studio), I have: main_savitch_4::string::string(const char str[ ] = “”) in mystring.h and added to in mystring.cpp:

main_savitch_4::string::string(const char str[ ] = ""){
    allocated = 0;  
    current_length = 0;
    start = new char[0];
}, which defines the private variables. 

I get the following errors:

c:\users\erice\documents\c++_2\lab04\rice_lab04_2\rice_lab04_2\mystring.cpp(13): error C2572: 'main_savitch_4::string::string' : redefinition of default parameter : parameter 1
1>          c:\users\erice\documents\c++_2\lab04\rice_lab04_2\rice_lab04_2\mystring.h(88) : see declaration of 'main_savitch_4::string::string'
1>.  

What exactly is going wrong??? I don’t understand what = means in a function description

Answer 1

The compiler is telling you that you have the default parameter in the declaration and definition of the function. Remove it from the definition:

main_savitch_4::string::string(const char str[ ]) { ... }

I don’t understand what = means in a function description

It means you are providing a derfault parameter to a function. For example,

void foo(int i = 42); // declaration

The above means you can call foo without a parameter:

....
void foo(int i) { return i+100; } // definition

// call the function
foo(); // calls it as foo(42);
foo(123);