string to char conversion by atoi from a defined index

Question

Let's say I have char x[3] = "123"; and I would like to convert only index 1 and index2 "23" of the char array, can I do it by atoi?

I know I can do it by char z[2]; z[0]=x[1]; z[1]=x[2]; atoi(z); but it is not what I am asking for.

Answer 1

You can do this with

char x[4];
int i;

strcpy(x, "123");
i = atoi(x + 1);

Because x is a pointer to char, x + 1 is a pointer to the next char. If you try to print with

printf("%s", x + 1);

You'l get 23 as the output.

Note though that you need to declare the length of the char array to be one more than the number of characters in it - to accommodate the ending \0.