Insertion Methods

The insert() methods let you insert a string object, a string array, a character, or several characters into a string object. The methods are similar to the append() methods, except that they take an additional argument, indicating where to insert the new material. This argument may be a position or an iterator. The material is inserted before the insertion point. Several of the methods return a reference to the resulting string. If pos1 is beyond the end of the target string or if pos2 is beyond the end of the string to be inserted, a method throws an out_of_range exception. If the resulting string will be larger than the maximum size, a method throws a length_error exception. Here are the prototypes for the various insert() methods:

basic_string& insert(size_type pos1, const basic_string& str);
basic_string& insert(size_type pos1, const basic_string& str,
                     size_type pos2, size_type n);
basic_string& insert(size_type pos, const charT* s, size_type n);
basic_string& insert(size_type pos, const charT* s);
basic_string& insert(size_type pos, size_type n, charT c);
iterator insert(const_iterator p, charT c);
iterator insert(const_iterator p, size_type n, charT c);
template<class InputIterator>
  void insert(iterator p, InputIterator first, InputIterator last);
iterator insert(const_iterator p, initializer_list<charT>); // C++11

For example, the following code inserts the string "former " before the b in "The banker.":

string st3("The banker.");
st3.insert(4, "former ");

Then the following code inserts the string " waltzed" (not including the !, which would be the ninth character) just before the period at the end of "The former banker.":

st3.insert(st3.size() - 1, " waltzed!", 8);