Allocate space for char

Question

String construct got space for the data by doing

new char[strlen(cp)+1];

Since there are only strlen(cp)characters in the string, what is the extra byte for?

Answer 1

For the special '\0' char which indicates end of string.

(Remember, C-style strings are null-terminated arrays).

Additional helpful notes:

• strlen does not count the '\0' (That's why you need this extra byte).
• strcpy does copy the '\0'.
• char str[7] = "String"; - Adds '\0' by itself.
• char str[] = {'S','t','r','i','n','g'} - Does not add '\0'.
• char str[7] = {'S','t','r','i','n','g'} - Will add '\0'.

Answer 2

In C based Strings there is always a special character at the end of string '\0' which also needs an extra byte. This is why we need an extra character and we need array of strlen(str)+1 to store the string.