Templates

Templates in C++

The keyword template is used to define the function template and class template.


It is a way to make your function or class generalize as far as the data type is a concern.

The template is a simple and yet very powerful tool in C++. The simple idea is to pass data type as a parameter so that we don’t need to write the same code for different data types. For example, a software company may need sort() for different data types. Rather than writing and maintaining the multiple codes, we can write one sort() and pass data type as a parameter.

C++ adds two new keywords to support templates: ‘template’ and ‘typename’. The second keyword can always be replaced by the keyword ‘class’.

Function template is also known as the generic template.

template<class type> type func_name(type arg1, ...);

Normal Example:

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#include<iostream.h>

#include<conio.h>

int big (int a, int b)

{

if(a>b)

return(a);

else

return(b);

}

int main()

{

cout<<big(4,5);

cout<<big(4.5, 6.5);

getch();

}

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Using Template:

#include<iostream.h>

#include<conio.h>

template <class X> 

X big( X a, X b)

{

if(a>b)

return(a);

else

return(b);

}

int main()

{

cout<<big(4,5);

cout<<big(4.5, 6.5);

getch();

}


or more than one template

#include<iostream.h>

#include<conio.h>

template <class X, Class Y> 

X big( X a, Y b)

{

if(a>b)

return(a);

else

return(b);

}

int main()

{

cout<<big(4,5);

cout<<big(4.5, 6.5);

getch();

}

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