Templates in C++ are a powerful feature that allows you to write generic code. This means you can create functions and classes that work with different data types without rewriting the same code multiple times.<\/p>\n\n\n\n
A template is a blueprint that tells the compiler to generate functions or classes for any data type.<\/p>\n\n\n\n
It removes code repetition and improves flexibility.<\/p>\n\n\n\n
Templates are useful because they:<\/p>\n\n\n\n
There are two main types:<\/p>\n\n\n\n
A function template allows a single function to work with different data types.<\/p>\n\n\n\n
template <typename T><\/code><\/pre>\n\n\n\nExample of Function Template<\/h2>\n\n\n\n#include <iostream>
using namespace std;
template <typename T>
T add(T a, T b) {
return a + b;
}
int main() {
cout << add(10, 20) << endl;
cout << add(5.5, 2.5) << endl;
return 0;
}<\/code><\/pre>\n\n\n\nOutput<\/h2>\n\n\n\n30
8<\/code><\/pre>\n\n\n\nHow It Works<\/h2>\n\n\n\n\nT<\/code> is a placeholder for any data type<\/li>\n\n\n\n- Compiler automatically decides the type<\/li>\n\n\n\n
- Same function works for int, float, double, etc.<\/li>\n<\/ul>\n\n\n\n
Class Templates<\/h1>\n\n\n\n
A class template allows a class to work with different data types.<\/p>\n\n\n\n
Syntax<\/h2>\n\n\n\ntemplate <typename T>
class ClassName {
T data;
};<\/code><\/pre>\n\n\n\nExample of Class Template<\/h2>\n\n\n\n#include <iostream>
using namespace std;
template <typename T>
class Box {
public:
T value;
void setValue(T v) {
value = v;
}
T getValue() {
return value;
}
};
int main() {
Box<int> b1;
b1.setValue(100);
cout << b1.getValue() << endl;
Box<string> b2;
b2.setValue(\"Hello\");
cout << b2.getValue() << endl;
return 0;
}<\/code><\/pre>\n\n\n\nOutput<\/h2>\n\n\n\n100
Hello<\/code><\/pre>\n\n\n\nHow Class Templates Work<\/h1>\n\n\n\n\n- One class works for multiple data types<\/li>\n\n\n\n
- Type is defined when creating an object<\/li>\n\n\n\n
- Same logic is reused<\/li>\n<\/ul>\n\n\n\n
Real-Life Example<\/h1>\n\n\n\n
Think of a template like a form:<\/p>\n\n\n\n
\n- One form can be used for students, employees, or customers<\/li>\n\n\n\n
- Only the data changes, not the structure<\/li>\n<\/ul>\n\n\n\n
This is how templates work in programming.<\/p>\n\n\n\n
Advantages of Templates<\/h1>\n\n\n\n\n- Reduce repetitive code<\/li>\n\n\n\n
- Improve reusability<\/li>\n\n\n\n
- Support multiple data types<\/li>\n\n\n\n
- Make programs scalable<\/li>\n\n\n\n
- Used heavily in STL<\/li>\n<\/ul>\n\n\n\n
Common Mistakes with Templates<\/h1>\n\n\n\n\n- Forgetting template declaration<\/li>\n\n\n\n
- Using wrong data types<\/li>\n\n\n\n
- Not understanding type deduction<\/li>\n\n\n\n
- Mixing incompatible operations<\/li>\n<\/ul>\n\n\n\n
Difference Between Function and Class Templates<\/h1>\n\n\n\nFunction Template<\/th> Class Template<\/th><\/tr><\/thead> Works with functions<\/td> Works with classes<\/td><\/tr> Used for operations<\/td> Used for data structures<\/td><\/tr> Simpler usage<\/td> More complex structure<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nApplications of Templates<\/h1>\n\n\n\n
Templates are used in:<\/p>\n\n\n\n
\n- STL containers (vector, map, list)<\/li>\n\n\n\n
- Generic algorithms<\/li>\n\n\n\n
- Data structure implementation<\/li>\n\n\n\n
- Reusable libraries<\/li>\n\n\n\n
- Large software systems<\/li>\n<\/ul>\n\n\n\n
Why Templates are Important<\/h1>\n\n\n\n
Templates are important because they:<\/p>\n\n\n\n
\n- Enable generic programming<\/li>\n\n\n\n
- Reduce code repetition<\/li>\n\n\n\n
- Improve performance and scalability<\/li>\n\n\n\n
- Are a core part of modern C++<\/li>\n<\/ul>\n\n\n\n
Conclusion<\/h2>\n\n\n\n
Templates in C++ are a powerful feature that allows writing flexible and reusable code. By using function and class templates, developers can create programs that work with multiple data types efficiently without rewriting code.<\/p>\n\n\n