i'm a noob just started to learn programing

what do these lines mean:

double complex::realPart() const
{
return real;
}


complex operator+ (const complex& lhs,
const complex& rhs)
{
return complex(lhs.real+rhs.real, lhs.imag+rhs.imag);
}

This defines a member function of the class "complex" that returns the real part of a complex number. For example, if "z" is an instance of class complex, then "z.realPart()" returns a double that presumably represents the real part of the complex number z. The "const" qualifier simply means that this function doesn't modify any part of the complex number it is called on (i.e., you can assume that the variable z is not changed by invoking "z.realPart()").
This overloads the "+" operator so that you can add two complex numbers the same way you'd add two ints or two doubles. For example, if "a" and "b" are two instances of class complex, then you could add them by using "a + b" like you would for other arithmetic types.

Are there more specific things you don't understand?

thank you for answearing me one more thing would help.
i've inserted my comments are they right?

complex operator* (const complex& lhs, const complex& rhs)
//overloading of complex multiplication
{
return complex(lhs.real*rhs.real - lhs.imag*rhs.imag,
lhs.real*rhs.imag+lhs.imag*rhs.real);

//complex multiplication is used to solve problem?
}

how far off am i with the comments? thanx again