public member function
<string>

std::string::find_last_not_of

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;
string (1)
size_t find_last_not_of (const string& str, size_t pos = npos) const noexcept;
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 noexcept;
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 or equal than 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.

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.

Example

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// 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;
}


[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