Templates in C++

Templates in C++

Templates in C++

Templates in C++

1.1 What is Templates in C++

1.2 How templates work

1.3 Example of template

1.4 Difference between function overloading and template.

1.1 What is Templates in C++

Templates in C++ is a simple idea to pass data type as a parameter so that we don't need to write the same code for the different data type.

In C++ we have two keywords to support template "template" and "typename" the second keyword can be replaced by keyword "class".

1.2 How templates work

Our code will contain only one function but based on our program compiler creates a copy of our function of the required data type.

How templates work

In the above program, we wrote a function to find the maximum out of two inputs and we are using a template to set the data type of myMax function according to the input.

For using a template:

1. we have to declare template like (template<typename T>).
2. Then instead of declaring the function as  (int myMax/char MyMax/float MyMax/double MyMax) declare it as T myMax (replace data type by T).
3. Replace the data type of variable(int x/double x/float x..) by T x.

1.3 Example of Template:

#include <iostream> using namespace std;  // One function works for all data types.  This would work template <typename T> T myMax(T x, T y) {    return (x > y)? x: y; }    int main() {   cout << myMax<int>(2, 8) << endl;  // Call myMax for int   cout << myMax<double>(5.0, 8.0) << endl; // call myMax for double   cout << myMax<char>('k', 'g') << endl;   // call myMax for char      return 0; }

Output:

8
8
k

1.4 Difference between function overloading and templates

Both are an example of polymorphism. Templates are used when multiple functions do identical operation while overloading is used when multiple functions do a similar operation.