cpp/string/basic string/rfind: Unterschied zwischen den Versionen

Aktuelle Version vom 1. Juli 2013, 20:47 Uhr

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Finds the last substring equal to the given character sequence. Search begins at pos, i.e. only the substring [0, pos) is considered in the search. If npos is passed as pos whole string will be searched.

1) Finds the last substring equal to str.

2) Finds the last substring equal to the first count characters of the character string pointed to by s. s can include null characters.

3) Finds the last substring equal to the character string pointed to by s. The length of the string is determined by the first null character.

4) Finds the last character ch.

[Bearbeiten] Parameter

[Bearbeiten] Rückgabewert

[Bearbeiten] Beispiel

#include <string>
#include <iostream>
 
void print(std::string::size_type n, std::string const &s)
{
  if(n == std::string::npos)
    std::cout << "not found\n";
  else
    std::cout << "found: " << s.substr(n) << '\n';
}
 
int main()
{
  std::string::size_type n;
  std::string const s = "This is a string";
 
  // search backwards from beginning of string
  n = s.rfind("is");
  print(n, s);
  // search backwards from position 4
  n = s.rfind("is", 4);
  print(n, s);
  // find a single character
  n = s.rfind('s');
  print(n, s);
  // find a single character
  n = s.rfind('q');
  print(n, s);
}

found: is a string
found: is is a string
found: string
not found

[Bearbeiten] Siehe auch