Thread: Simple String Manipulation (Beginner question)

I've just started learning C and am having some trouble.

Lets say you have these two strings.

char a [5] = "abcd";
char b [3] = "zz";

I want to use strcpy() and strcat() to change b into "bd".

Something like,

strcpy(b, a[1]);
strcat(b, a[3]);

Clearly, this does not work.
a[1] is not a string. I have no idea how to get a "b" string from the variable a.

Any help?

If the string is actually that short you can manipulate it as a character array.

strcpy(string,string[location]) wont work b/c you are using a function to copy one string into another to copy one character into a string. If you want to copy one char to a string you should try
strcpy(string,"c"). I think anything b/w quotes can be considered a string literal. You should google strcpy.

In order to get "b" from the string a, you would have to do &a[1]. However, because both strcpy and strcat expect null terminated strings, you can't really use them in your example. On the other hand, you could use something like strncpy and strncat to achieve what you want:

Code:

char a[] = "abcd";
char b[] = "zz";

strncpy(b, &a[1], 1);
strncat(b, &a[3], 1);

However, for simple cases like what you've got, you're MUCH better using direct assignment (IE: using strcpy or memcpy with "bd" as the concatenating argument)