std::string::find_last_not_of

public member function

<string>

std::string::find_last_not_of

• C++98
• C++11

string (1)	size_t find_last_not_of (const string& str, size_t pos = npos) const;
c-string (2)	size_t find_last_not_of (const char* s, size_t pos = npos) const;
buffer (3)	size_t find_last_not_of (const char* s, size_t pos, size_t n) const;
character (4)	size_t find_last_not_of (char c, size_t pos = npos) const;

Find non-matching character in string from the end

Searches the string for the last character that does not match any of the characters specified in its arguments.

When pos is specified, the search only includes characters at or before position pos, ignoring any possible occurrences after pos.

Parameters

str

Another string with the set of characters to be used in the search.

pos

Position of the last character in the string to be considered in the search.
Any value greater than, or equal to, the string length (including string::npos) means that the entire string is searched.
Note: The first character is denoted by a value of 0 (not 1).

s

Pointer to an array of characters.
If argument n is specified (3), the first n characters in the array are used in the search.
Otherwise (2), a null-terminated sequence is expected: the length
of the sequence with the characters used in the search is determined by
the first occurrence of a null character.

n

Number of character values to search for.

c

Individual character to be searched for.

size_t is an unsigned integral type (the same as member typestring::size_type).

Return Value

The position of the first character that does not match.
If no such characters are found, the function returns string::npos.

size_t is an unsigned integral type (the same as member typestring::size_type).

Example

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

// string::find_last_not_of #include <iostream> // std::cout #include <string> // std::string #include <cstddef> // std::size_t int main () { std::string str ("Please, erase trailing white-spaces \n"); std::string whitespaces (" \t\f\v\n\r"); std::size_t found = str.find_last_not_of(whitespaces); if (found!=std::string::npos) str.erase(found+1); else str.clear(); // str is all whitespace std::cout << '[' << str << "]\n"; return 0; }

Edit & Run

[Please, erase trailing white-spaces]

Complexity

Unspecified, but generally up to linear in the string length (or pos) times the number of characters to match (worst case).

Iterator validity

No changes.

Data races

The object is accessed.

Exception safety

If s does not point to an array long enough, it causes undefined behavior.
Otherwise, the function never throws exceptions (no-throw guarantee).

See also

string::find

Find content in string (public member function
)

string::find_last_of

Find character in string from the end (public member function
)

string::find_first_not_of

Find absence of character in string (public member function
)

string::replace

Replace portion of string (public member function
)

string::substr

Generate substring (public member function
)

http://www.cplusplus.com/reference/string/string/find_last_not_of/