Print vector m[][] in C++

Question

I need to print the strings from this 3d matrix using an iterator.

This is the declaration

vector <string> transicoes[estados.size()][alfabeto.size()];

I tried printing like this

printf("%s", transicoes[i][j][k]);

but I get this error message:

cannot pass objects of non-trivially-copyable type

How can I do this?

EDIT: changed to cout and it works now, thanks

`printf` is a C function, and since C doesn't have `string`s, `printf`doesn't know a `string` from a hole in the ground. Because `printf` uses a variable argument list, the compiler may not even give you a warning. — user4581301, Jun 04 '17 at 20:44
Possible duplicate of [C++ printf with std::string?](https://stackoverflow.com/questions/10865957/c-printf-with-stdstring) — user4581301, Jun 04 '17 at 21:04

score 3 · Answer 1 · answered Jun 04 '17 at 20:48

3

The problem is that C functions are not compatible with C++ structures. Try doing this instead:

printf("%s", transicoes[i][j][k].c_str());

The c_str() call returns a const char* to a null-terminated character array with data equivalent to those stored in the string, which is a C-like string.

But if you are working with C++, you should use the stream operators << and >>. The code would then loop like this:

std::cout << transicoes[i][j][k] << endl;

answered Jun 04 '17 at 20:48

pastaleg

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Thanks it worked , I had to switch to from C to C++ without almost any knowledge of C++ to deal with a lot of dynamic sized vectors. So yeah... – Jun 04 '17 at 20:53

Print vector m[][] in C++

1 Answers1