strcpy函数的作用是什么

char *strcpy(char *dest, const char *src)

#include <stdio.h>
#include <string.h>
int main()
{
   char src[40];
   char dest[100];
  
   memset(dest, &#39;\0&#39;, sizeof(dest));
   strcpy(src, "This is runoob.com");
   strcpy(dest, src);
 
   printf("最终的目标字符串： %s\n", dest);
   
   return(0);
}

#include <stdio.h>
#include <string.h>
 
int main ()
{
  char str1[]="Sample string";
  char str2[40];
  char str3[40];
  strcpy (str2,str1);
  strcpy (str3,"copy successful");
  printf ("str1: %s\nstr2: %s\nstr3: %s\n",str1,str2,str3);
  return 0;
}

str1: Sample string
str2: Sample string
str3: copy successful