C++ Vector Library - insert() Function

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Description

The C++ function std::vector::insert() extends vector by inserting new elements in the container. Reallocation happens if there is need of more space

This function increases container size by n.

Declaration

Following is the declaration for std::vector::insert() function form std::vector header.

iterator insert (const_iterator position, initializer_list<value_type> il);

Parameters

• position − Index in the vector where new element to be inserted.

• il − Initializer list object.

Return value

Returns an iterator which points to the newly inserted element.

Time complexity

Linear i.e. O(n)

Example

The following example shows the usage of std::vector::insert() function.

#include <iostream>
#include <vector>

using namespace std;

int main(void) {
   vector<int> v = {1, 2};
   auto ilist = {3, 4, 5};

   v.insert(v.begin() + 2, ilist);

   for (int i = 0; i < v.size(); ++i)
      cout << v[i] << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

1
2
3
4
5