std::basic_string::substr

Parameters

pos

Position of the first character to be copied as a substring.
If this is equal to the string length, the function returns an empty string.
If this is greater than the string length, it throws out_of_range.
Note: The first character is denoted by a value of 0 (not 1).

len

Number of characters to include in the substring (if the string is shorter, as many characters as possible are used).
A value of basic_string::npos indicates all characters until the end of the string.

Return Value

Example

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// string::substr
#include <iostream>
#include <string>

int main ()
{
  std::string str="We think in generalities, but we live in details.";
                                              // (quoting Alfred N. Whitehead)

  std::string str2 = str.substr (12,12);         // "generalities"

  std::string::size_type pos = str.find("live"); // position of "live" in str

  std::string str3 = str.substr (pos);           // get from "live" to the end

  std::cout << str2 << ' ' << str3 << '\n';

  return 0;
}

generalities live in details.

Complexity

Iterator validity

Data races

Exception safety

See also

basic_string::replace

Replace portion of string (public member function)

basic_string::data

Get string data (public member function)

basic_string::find

Find first occurrence in string (public member function)

basic_string::assign

Assign content to string (public member function)

basic_string::basic_string

Construct basic_string object (public member function)