Question about Arrays and Strings

[bryanr59]

Question 1: About Arrays

Must I specify a size when initializing an array?

In my program the user enters a number into the console, and i want to create an array of that size.


Question 2: About Strings
Can I make string arrays? And why isn't a string a data type?



I appreciate any help!

[Zhuge]

1: Yes, unless you use dynamic memory allocation via new or malloc.

2: Yes. std::strings are a typedef for a basic_string of chars, which is an STL container, not an base type.

[bryanr59]

#include <iostream>
#include <new>
using namespace std;

int main ()
{
  int n,o;

  cout << "How many questions do you wish to answer?" << endl;
  cin >> n;
  cout << "How many characters will you use per answer?" << endl;
  cin >> o;
  char userAnswers[n][o];

  return 0;
}

I couldn't figure out how to do the DMA. But not even this seems to work for me. I get these errors:

expected constant expression
cannot allocate an array of constant size 0
expected constant expression
cannot allocate an array of constant size 0
missing subscript
unknown size

[firedraco]

You will need to do this:

char* userAnswers = new char[n][o];

To make an array of strings instead, just use string instead of char. Although I would suggest using a vector, since then you won't have to prompt them for how many questions they are going to answer. Also, if you use strings, you don't need a question for how many characters per answer, since strings are dynamically sized for you.