Search

C++ offers many ways to search in a string. Each way exists in various overloaded forms.

ℹ️ Search is called find
It seems a bit odd but the algorithms for searching in a string start with the prefix “find”. If the search was successful, we get an index of type std::string::size_type, if not, we get the constant std::string::npos. The first character has the index 0.

The find algorithms support:

• searching for a character from a C or C++ string.
• searching forward and backward.
• searching for the presence or lack of characters in a C or C++ string.
• starting the search at an arbitrary position in the string.

The arguments of all six variations of the find function follow a similar pattern. The first argument is the text we are searching for. The second argument holds the start position of the search, and the third represents for the number of characters starting from the second argument.

Here are the six variations:

Methods	Description
str.find(...)	Returns the first position of a character, a C or C++ string in str.
str.rfind(...)	Returns the last position of a character, a C or C++ string in str.
str.find_first_of(...)	Returns the first position of a character from a C or C++ string in str.
str.find_last_of(...)	Returns the last position of a character from a C or C++ string in str.
str.find_first_not_of(...)	Returns the first position of a character in str, which is not from a C or C++ string.
str.find_last_not_of(...)	Returns the last position of a character in str, which is not from a C or C++ string.

Find variations of the string