What is the meaning of & in c++?

Question

I want to know the meaning of & in the example below:

class1 &class1::instance(){

///something to do

}

Answer 1

It means that the variable it is not the variable itself, but a reference to it. Therefore in case of its value change, you will see it straight away if you use a print statement to see it. Have a look on references and pointers to get a more detailed answer, but basecally it means a reference to the variable or object...