How to Write C++ Template Function That Will Return Maximum of Two Numbers

In this C++ tutorial, we explain how to write a C++ template function that will return a maximum value of two given numbers. Here, the numbers provided to the function can be of arbitrary data types. Let us tackle this problem immediately.

Template C++ Function for Finding Max Value

The template function definition is given below.

template<typename T>
T maxFunction(T a, T b)
{
    if (a>= b)
    {
        return a;
    }
    else
    {
        return b;    
    }
}

Here, to define a template function, we first need to use

template<typename T>

This means that we are defining a template function where T will be used to denote a generic data type that the function will accept. Then, we define the function using T as a data type of the input arguments of the function:

T maxFunction(T a, T b)
{
    if (a>= b)
    {
        return a;
    }
    else
    {
        return b;    
    }
}

The complete program together with a driver main function is given below

/*
PROBLEM: Define a C++ template function that returns 
the maximum number of two given numbers of the same data type.
*/
#include<iostream>
#include<cstdlib>

using namespace std;

template<typename T>
T maxFunction(T a, T b)
{
    if (a>= b)
    {
        return a;
    }
    else
    {
        return b;    
    }
}


int main()
{
   float n1=4.7;
   float n2=5.1;
   float n3;

   n3=maxFunction<float>(n2,n1);

   cout<<"The maximum value is "<<n3<<endl;

    return 0;
}

We define two floats, and to call the function we use

   n3=maxFunction<float>(n2,n1);

It is very important to specify the type of the data type that our template function will accept. We do that by using “<float>”. Here, instead of “<float>” you can use also “<int>” or any other data type to notify the compiler of the data type that the function should accept.