Answers for ".substr c++"

c++ substring

// 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 (3,5);     // "think"

  std::size_t 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;
}

cpp substring

#include <iostream>
#include <string>

using namespace std;

void cpp_strings()
{
    string unformatted_full_name { "StephenHawking" };

    string first_name = unformatted_full_name.substr(0, 7);
    // string first_name { unformatted_full_name, 0, 7 };
    string last_name = unformatted_full_name.substr(7, 7);
    string formatted_full_name = first_name + last_name;

    formatted_full_name.insert(7, " ");
    cout << formatted_full_name;
}

int main()
{
    cpp_strings();
    return 0;
}

string c++ substr

#include <string>
#include <iostream>
 
int main()
{
    std::string a = "0123456789abcdefghij";
 
    // count is npos, returns [pos, size())
    std::string sub1 = a.substr(10);
    std::cout << sub1 << 'n';
 
    // both pos and pos+count are within bounds, returns [pos, pos+count)
    std::string sub2 = a.substr(5, 3);
    std::cout << sub2 << 'n';
 
    // pos is within bounds, pos+count is not, returns [pos, size()) 
    std::string sub4 = a.substr(a.size()-3, 50);
    // this is effectively equivalent to
    // std::string sub4 = a.substr(17, 3);
    // since a.size() == 20, pos == a.size()-3 == 17, and a.size()-pos == 3
 
    std::cout << sub4 << 'n';
 
    try {
        // pos is out of bounds, throws
        std::string sub5 = a.substr(a.size()+3, 50);
        std::cout << sub5 << 'n';
    } catch(const std::out_of_range& e) {
        std::cout << "pos exceeds string sizen";
    }
}

substring function in c++

string sub_string=main_string.substr(first_pos_of_the_substring_from_main_string,length_of_the_substring_from_main_string_starting_from_the_first_position