strcat problems

This doesn't work as I'd expect it to. Obviously I'm doing something wrong, but I can't see it. Please can someone give me a nudge.

Code extract:

Code:

   char *article[] = { " the ", " a ", " some ", " any " };
   const int size = 50;
   char sentence[ size ];
   int number;

   for ( int i = 0; i < size; i++ )
      sentence[ i ] = ' ';
   
   for ( int i = 0; i < 20; i++ ) {
      number = rand() % 3;    
      cout << sentence << '\n';
      strcat( article[ number ], sentence );
      
      cout << sentence << '\n';
      
      for ( int j = 0; j < size; j++ )
         sentence[ j ] = ' ';
   }

Code:

strcat( article[ number ], sentence );

strcat(dst, src) appends src to dst, which means that dst = dst + src

And make sure sentence contains enough space.

Well, I understand what strcat does, but I need it to copy the string found at a certain location in the article[] array of strings and then place it into the sentence array. It gives me a weird error at run-time and I don't know what I'm doing wrong.

Can you explain what you're trying to achieve? Are you trying to make a sentence with 20 words?

> const int size = 50;
If the answer to the above question is yes, you need more than 50, maybe 80 or 100.

> for ( int i = 0; i < size; i++ )
> sentence[ i ] = ' ';
If you want to erase sentence, use:
sentence[0] = '\0';
or:
strcpy(sentence,"");

> number = rand() % 3;
If you want a number between 0 and 3, use:
number = rand() % 4;

> strcat( article[ number ], sentence );
I think you want:
> strcat( sentence, article[ number ] );

> for ( int j = 0; j < size; j++ )
> sentence[ j ] = ' ';
Are you sure you want to do this within the for-loop?

Aha - Brainwave! Or coffee. Either way I figured it out. Thanks for the assistence people.

Here's the code:

Code:

#include <iostream>
using std::cout;
using std::cin;

#include <cstring>
#include <ctime>
#include <cstdlib>

int main()
{
   char *article[] = { "the ", "a ", "some ", "any " };
   char *noun[]    = { "boy ", "girl ", "dog ", "town ", "car " };
   char *verb[]    = { "ran ", "walked ", "skipped ", "drove ", "jumped " };
   char *preposition[] = { "to ", "from ", "over ", "under ", "on " };
   const int size = 50;
   char sentence[ size ];
   int number;
   
   srand( time( 0 ) );
   
   for ( int i = 0; i < size; i++ )
      sentence[ i ] = '\0';
   
   for ( int i = 0; i < 20; i++ ) {
      number = rand() % 4;    
      strcat( sentence, article[ number ] );
      
      number = rand() % 5;
      strcat( sentence, noun[ number ] );
      
      number = rand() % 5;
      strcat( sentence, verb[ number ] );
      
      number = rand() % 5;
      strcat( sentence, preposition[ number ] );
      
      number = rand() % 4;
      strcat( sentence, article[ number ] );
      
      number = rand() % 5;
      strcat( sentence, noun[ number ] );
      
      cout << sentence << '\n';
      
      for ( int j = 0; j < size; j++ )
         sentence[ j ] = '\0';
   }   
   
   cin.get();
   return 0;
}