std::basic_string::substr

From cppreference.com
< cpp‎ | string‎ | basic string
 
 
 
std::basic_string
 
basic_string substr( size_type pos = 0,
                     size_type count = npos ) const;

Returns a substring [pos, pos+count). If the requested substring extends past the end of the string, or if count == npos, the returned substring is [pos, size()).

Contents

[edit] Parameters

pos - position of the first character to include
count - length of the substring

[edit] Return value

  1. An empty string if pos == size().
  2. String containing the substring [pos, pos+count).

[edit] Exceptions

std::out_of_range if pos > size()

[edit] Complexity

Linear in count

[edit] Example

#include <string>
#include <iostream>
 
int main()
{
    std::string a = "0123456789abcdefghij";
 
    std::string sub1 = a.substr(10);
    std::cout << sub1 << '\n';
 
    std::string sub2 = a.substr(5, 3);
    std::cout << sub2 << '\n';
 
    std::string sub3 = a.substr(12, 100);
    std::cout << sub3 << '\n';
 
    std::string sub4 = a.substr(a.size()-3, 50);
    std::cout << sub4 << '\n';
}

Output:

abcdefghij
567
cdefghij
hij

[edit] See also

copies characters
(public member function)
returns the number of characters
(public member function)
find characters in the string
(public member function)