C-Style Character String

Question

I want to connect two C-style character strings and store the result in a dynamic char array.

int main()
{
  char word1[] = "hello";
  char word2[] = "haha";
  auto ptr = new char[20];
  strcpy(ptr,strcat(word1,word2));
  cout<<ptr<<endl;
  return 0;
}

The compiler says there is a "segmentation fault" at the statement strcpy(ptr,strcat(word1,word2));. Why does the compiler say that?

the segfault is not from your compiler but when you run the executable. A segfault reported while you run the compiler would be a bug in your compiler — 463035818_is_not_an_ai, Jun 27 '22 at 08:06
You got the order wrong; you want `strcat(strcpy(ptr, word1), word2);` — molbdnilo, Jun 27 '22 at 08:11
`auto ptr = new char[20];` is overly complex here. `char buf[20];` is all that's needed. — Pete Becker, Jun 27 '22 at 12:59

score 2 · Accepted Answer · answered Jun 27 '22 at 08:06

Like this

strcpy(ptr, word1);
strcat(ptr, word2);

You need to use ptr for both operations, the copy and the concatenation.

In your version strcat(word1,word2) tries to concatenate word2after the end of word1. But there is no accessible memory there, so you get a segmentation fault.

C-Style Character String

1 Answers1