Question

I’m trying to write a code which stores strings in an array. I’m trying to do it with char* but I couldn’t achieve. I search the net but couldn’t find an answer. I’ve tried the code below, but it didn’t compile.I use string stream because at some point I need to concatenate a string with an integer.

stringstream asd;
asd<<"my name is"<<5;
string s = asd.str();
char *s1 = s;

Answer 1

> I’m trying to write a code which stores strings in an array.

Well, first you’ll need an arary of strings. I don’t like using naked arrays, so I use std::vector:

std::vector<std::string> myStrings;

But, I understand you have to use an array, so we’ll use an array instead:

// I hope 20 is enough, but not too many.
std::string myStrings[20];
int j = 0;

> I use string stream because …

Okay, we’ll use stringstream:

std::stringstream s;
s << "Hello, Agent " << 99;
//myStrings.push_back(s.str()); // How *I* would have done it.
myStrings[j++] = s.str(); // How *you* have to do it.

That gets us one string, but you want an array of them:

for(int i = 3; i < 11; i+=2) {
  s.str(""); // clear out old value
  s << i << " is a" << (i==9?" very ":"n ") << "odd prime.";
  //myStrings.push_back(s.str());
  myStrings[j++] = s.str();
}

Now you have an array of strings.

Complete, tested program:

#include <sstream>
#include <iostream>

int main () {
  // I hope 20 is enough, but not too many.
  std::string myStrings[20];
  int j = 0;

  std::stringstream s;
  s << "Hello, Agent " << 99;
  //myStrings.push_back(s.str()); // How *I* would have done it.
  myStrings[j++] = s.str(); // How *you* have to do it.

  for(int i = 3; i < 11; i+=2) {
    s.str(""); // clear out old value
    s << i << " is a" << (i==9?" very ":"n ") << "odd prime.";
    //myStrings.push_back(s.str());
    myStrings[j++] = s.str();
  }

  // Now we have an array of strings, what to do with them?
  // Let's print them.
  for(j = 0; j < 5; j++) {
    std::cout << myStrings[j] << "\n";
  }
}