Declare in C++

To declare a class in C++, we use the class keyword followed by the name of the class. Inside the class, we can declare its data members and member functions. Here's an example:

class MyClass {
    private:
        int myInt;
        float myFloat;
    
    public:
        void setInt(int i) {
            myInt = i;
        }
        
        float getFloat() {
            return myFloat;
        }
};

In this example, we declare a class called MyClass with two private data members: myInt (an integer) and myFloat (a float). We also declare two member functions: setInt() to set the value of myInt, and getFloat() to retrieve the value of myFloat.

To use the class, we can create an instance of the class like this:

MyClass myObj;

We can then call the member functions like this:

myObj.setInt(5);
float f = myObj.getFloat();

In this example, we set the value of myInt to 5 using setInt(), and retrieve the value of myFloat using getFloat().