1.2 Substrings

Accessing substrings is quite easy with std::string, using the substr() member function. In this example, hello contains the five characters, hello:

std::string text("Hello world!");
std::string hello(text.substr(0, 5));

Here's the signature of substr():

std::string
std::string::substr(std::size_t offset, std::size_t length = std::string::npos)

std::string::npos is described in the Introduction. The default means to include the rest of the string.

Note that substr() returns a new string. To modify a substring, in situ, use std::string::replace() or std::string::insert().

Here's an example of replacing car with bus in the How many will fit in that car?:

std::string text("How many will fit in that car?");
text.replace(26, 3, "bus");

replace() has many overloads. Refer to pages like this and this for details.