Pair

A pair is nothing but a group of two elements. In C++, pairs can be dealt using the header <utility>. A pair can be defined as follows.

pair <arg1_type, arg2_type> pair_name;

And, values can be given directly or by using the make_pair() function as pair_name = make_pair(arg1, arg2); where pair_name.first and pair_name.second can be used to access arg1 and arg2 respectively.

In the 2D coordinate plane, each point can be considered as a pair. This code can be used to find the midpoint of two points in the 2D coordinate plane by considering them as pairs.


	            pair <float, float> p1(1, 0);

	            pair <float, float> p2(0, 1);


	            pair <float, float> p3;

	            p3 = make_pair((p1.first + p2.first) / 2, (p1.second + p2.second) / 2);


	            cout << "Midpoint : " << "(" << p3.first << ", " << p3.second << ")";

It outputs (0.5, 0.5) [Try It Yourself!], which is the midpoint of (1, 0) and (0, 1).

A pair can also be declared as pair <arg1_type, arg2_type> p2(p1); where p1 is an already declared pair.

Fill in the Blanks

The header file is needed to deal with pairs in C++.

Pair - C++ container