String

A string in C++ is a sequence of characters. Strings are used to store text, such as names, addresses, and messages.

To create a string in C++, you can use the std::string class. The std::string class is a header file called <string>.

For example, the following code creates a string named my_string and initializes it to the value "Hello, world!".

std::string my_string = "Hello, world!";

You can also use the "" and '' characters to create strings. However, it is generally considered best practice to use the std::string class when creating strings in C++.

String functions

The std::string class provides a variety of functions for working with strings. Some of the most common string functions include:

length(): Returns the length of the string.
empty(): Returns true if the string is empty, and false otherwise.
compare(): Compares two strings and returns a value indicating which string is greater than, less than, or equal to the other string.
find(): Finds the first occurrence of a substring in a string and returns the index of the substring.
substr(): Extracts a substring from a string.
append(): Appends one string to the end of another string.

String examples

The following examples show how to use some of the most common string functions in C++:

// Create a string.

std::string my_string = "Hello, world!";

// Get the length of the string.

int length = my_string.length();

// Check if the string is empty.

bool empty = my_string.empty();

// Compare the string to another string.

int comparison = my_string.compare("Goodbye, world!");

// Find the first occurrence of a substring in the string.

int index = my_string.find("world");

// Extract a substring from the string.

std::string substring = my_string.substr(0, 5);

// Append one string to the end of another string.

my_string.append("!");

Conclusion

Strings are a powerful tool in C++. They can be used to store text, manipulate text, and perform other tasks. The std::string class provides a variety of functions for working with strings.