insert函數

string& insert ( size_t pos1, const string& str, size_t pos2, size_t n );

Inserts a copy of a substring of str at character position pos1. The substring is the portion of str that begins at the character position pos2 and takes up to n characters (it takes less than n if the end of str is reached before).

例子(c++):

// inserting into a string

#include <iostream>

#include <string>

int main ()

{

std::string str="to be question";

std::string str2="the ";

std::string str3="or not to be";

std::string::iterator it;

// used in the same order as described above:

str.insert(6,str2); // to be (the )question

str.insert(6,str3,3,4); // to be (not )the question

str.insert(10,"that is cool",8); // to be not (that is )the question

str.insert(10,"to be "); // to be not (to be )that is the question

str.insert(15,1,':'); // to be not to be(:) that is the question

it = str.insert(str.begin()+5,','); // to be(,) not to be: that is the question

str.insert (str.end(),3,'.'); // to be, not to be: that is the question(...)

str.insert (it+2,str3.begin(),str3.begin()+3); // (or )

std::cout << str << '\n';

return 0;

}