copying contents of array1 into array2

[richdb]

Hi,
I am trying to write a program that asks for a string, enters it into array1, and then copies it into array2, which is empty. The program then displays array1 and array2. The problem is that I can't seem to get the first array to enter into the second. Im trying to do this using just pointers with arrays. I don't know any of the string functions yet, like strncpy() or similar ones. The section in red is where I try to copy array1 to array2. Probably makes no sense, but I'm stuck. Any help would be appreciated.

#include <stdio.h>

main()

{
      char string1[51],
           string2[51],
           *letter,
           *letter2;
           
           printf("\nPlease enter a string: ");
           gets(string1);
           
           /*PRINT STRING1*/
           for(letter = string1; *letter != '\0'; ++letter)
           printf("%c" , *letter);
           
           /*ASSIGN STRING1 TO STRING2*/
           for(letter2 = string2; *letter2 != '\0'; ++letter2) 
           string2[*letter2] = *letter;
           
          putchar('\n');
          
           /*PRINT STRING2*/
           for(letter2 = string2; *letter2 != '\0'; ++letter2)
           printf("%c" , *letter2);
           
           
}

[Tonto]

for(letter2 = string2, letter1 = string1; *letter1 != '\0'; ++letter2, ++letter1) 
	*letter2 = *letter1;

Assign both accessory pointers to the beginning of those strings. Then, while we're not at the end of the existing string we entered, make them equal, and increment both. This is often shortened to:

while(*d++ = *s++);

For a function like strcpy, copying the dest 's' from source 's'

[richdb]

Thanks tonto,
I didn't know you could write for loops like that. The output was correct, but it had some garbage characters at the end of it that I cant figure out.

Please enter a string: asdfjkl;
asdfjkl;
asdfjkl;↑εÉ|p♣æ|........m♣æ|▐┬┬w

[dude543]

Yes , thats true. Because you did'nt null terminated string2.

after the for loop

for(letter2 = string2, letter = string1; *letter != '\0'; ++letter2, ++letter) 
	*letter2 = *letter;

Notice that when you print string2, you test it until we reach a null.
we want to null terminate string2. so, add this

*letter2 = '\0';

[WaltP]

That's because the loop stopped before transferring the ending \0 from the source string. Add:

while(*d++ = *s++);
*d = '\0';

[richdb]

I can't see why the \0 gets cut off. Is it because this condition:

*letter != '\0'

leaves the \0 non inclusive?

[hk_mp5kpdw]

During the copy from one string to the other, you loop until you reach a NULL. Once you hit that NULL, you stop copying (the NULL does not get copied); so... you must then take the extra step to properly NULL terminate the new string.

[Maragato]

I can't see why the \0 gets cut off. Is it because this condition:

*letter != '\0'

leaves the \0 non inclusive?

'\0' is a scape character btw, takea look in strcpy function.