This page is provided for your information. In this course, please limit yourself to basic null-terminated strings. Do not use type string.
Remember that part of the goal of this course is to learn how to do things at a very basic level without relying on a library that hides how things work.
The C++ library provides a type called string. To use it, #include <string>.
The memory occupied by strings is managed using reference counts. So you should not try to do your own memory management with them. They are deleted automatically.
Here is a partial list of operations available for type string. In all of these, assume that s and t have type string.
string s = (string) "null-terminated string";
| The compiler will convert a null-terminated string to type string for you. |
s.length()
| The length of string s. |
s + t
The concatenation of s and t.
For example,
string s = "the cat " string t = "in the hat" string r = s + t;makes r be string "the cat in the hat". Strings s and t are not changed. |
s[k]
| This is the k-th character in string s (numbering from 0). |
s == t
| This is true if strings s and t have exactly the same characters, in the same order. So it is a sensible equality test for strings. You can also use comparisons such as < and > on strings. They compare using alphabetical order. |
s.c_str()
| A value of type string has a null-terminated string as part of it information. s.c_str() yields a pointer to that null-terminated string. It does not copy the null-terminated string, and this pointer becomes a dangling pointer if string s becomes inaccessible. The system does not remember that you have a pointer (of type char*) to part of the string's information. |