Converting an array of a fixed size to a string

[vipertherapper]

Hi, I'm just trying to do some type conversion. In Python or JavaScript, it's as easy as calling str() on your object.

Here is my code:

int GenChar()
{

    std::string P;
    srand (time(nullptr));
    int i;

    int arr[i];
    const std::string characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    for (int i = 1; i <=4; i++) {
        arr[i] = rand() % 26;
        std::cout << characters[arr[i]] << std::endl;

    }
    
};

I want to store the contents of arr in a string, P. How should I approach this?

The string, on execution, should be a "randomly" generated string of 4 uppercase characters.

[lastchance]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

#include <iostream> #include <string> #include <ctime> #include <cstdlib> using namespace std; string randWord( int L ) { const string alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; string word; for ( int i = 1; i <= L; i++ ) word += alphabet[rand()%26]; return word; } int main() { srand( time( 0 ) ); const int N = 10; cout << N << " random four-letter words (ahem) are:\n"; for ( int i = 0; i < N; i++ ) cout << randWord( 4 ) << '\n'; }

10 random four-letter words (ahem) are: XYNJ TQNX JLND TQXB STIA ZUKP JECF FTVV DAIM NQZA

[Thomas1965]

Slightly different approach:

#include <iostream>
#include <string>
#include <ctime>

using namespace std;

string RandomString(int length)
{
  string res;

  for (int i = 0; i < length; i++)
  {
    res += 'A' + (rand() % 26);
  }

  return res;
}

int main()
{
  srand((unsigned)time(nullptr));
  for (int i = 0; i < 10; i++)
  {
    cout << RandomString(4) << "\n";
  }
}

[vipertherapper]

Thomas, I like that a lot. Can you explain the following line of code to me?

res += 'A' + (rand() % 26);

How does the machine know to continue the sequence of the alphabet?

[vipertherapper]

Then, if I assigned the value of RandomString() to a variable, say P, like so:

P = RandomString(4);

How can I pass P to a new function, CrackP()?

I tried using CrackP(P), but my program can't resolve the type. I then tried returning P at the end of main, also to no avail.

How can I pass the value of P to other functions as a parameter?

Sorry for the silly questions. New to C++.

[Thomas1965]

Thomas, I like that a lot. Can you explain the following line of code to me?
res += 'A' + (rand() % 26);

'A' is sth. like 65 on most char sets. 'B' is 66 and so on. rand() % 26 will generate a number between 0 and 25.

+= append the character to the string - same as res = res + (rand() % 26);
% is the modulo operator

RandomString will return a string so your Crack function needs to accept a string as parameter.

string str = RandonString(4);

void Crack(string s);
{
  // some code here
}

Call it Crack(str);