Thread: Codeblocks,C++, rand() was not declared.

hopefully posted in right area (sorry if didnt).
hey there. learning c++ c++ dummies all-in-one second edition teach codeblocks (the reason why bought it).

ok, problem error such when building:

code:

error; 'rand' not declared in scope

here's sourcode (slightly modified books version. added prototype function).
rand() located in getsecretcode() function

code:

#include <iostream>  #include <sstream>    using namespace std;    string *getsecretcode();    int main()  {      string *newcode;      int index;        ( index = 0; index < 10; index++ )      {          newcode = getsecretcode();          cout << newcode << endl;      }        cout << "all done here" << endl;        return 0;  }    string *getsecretcode()  {      string *code = new string;      code->append("cr");        int randomnumber = rand();      ostringstream converter;      converter << randomnumber;        code->append(converter.str());      code->append("nq");        return code;  }

missing code wise?
didn't "#include" ?

rand defined in cstdlib (there no standard c++ random function yet). include:
#include <cstdlib>

have memory leaks in code don't delete created string
should avoid dynamically allocating stuff not needed.
can rewrite this:

code:

// long string might expensive copy, use reference  void createcopyexpensivestring(string & str) {  // dostuff  }    // short string, cheap copy  string createshortstring()  {     return "shortstring";  }    void main()  {    string str;    createcopyexpensivestring(str);    cout << str << endl;    string str2 = createshortstring();    cout << str2 << endl;  } // str , str2 go out of scope here , deleted automatically

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