C Tutorial/string.h/strncat

Материал из C\C++ эксперт
Перейти к: навигация, поиск

strncat

Item Value Header file string.h Declaration char *strncat(char *str1, const char *str2, size_t count); Function concatenates not more than count characters of *str2 to *str1 and terminates str1 with a null. Return returns *str1.

You have to ensure that str1 is large enough to hold both its str1 and str2.


<source lang="cpp">#include <stdio.h>

 #include <string.h>
 int main(void)
 {
   char s1[80], s2[80];
   unsigned int len;
   gets(s1);
   gets(s2);
   len = 79-strlen(s2);
   strncat(s2, s1, len);
   printf(s2);
   return 0;
 }</source>

Using strcat and strncat

<source lang="cpp">#include <stdio.h>

  1. include <string.h>

int main() {

  char s1[ 20 ] = "Happy "; 
  char s2[] = "New Year ";  
  char s3[ 40 ] = "";       
  
  printf( "s1 = %s\ns2 = %s\n", s1, s2 );
  printf( "strcat( s1, s2 ) = %s\n", strcat( s1, s2 ) );
  printf( "strncat( s3, s1, 6 ) = %s\n", strncat( s3, s1, 6 ) );
  printf( "strcat( s3, s1 ) = %s\n", strcat( s3, s1 ) );
  return 0;

}</source>

s1 = Happy
s2 = New Year
strcat( s1, s2 ) = Happy New Year
strncat( s3, s1, 6 ) = Happy
strcat( s3, s1 ) = Happy Happy New Year