confusing syntax

Question

Hi
Always for passing a reference to the function we used this syntax
```
void foo(myclass *par){
cout << par->att <<endl;
}
```
with * operator in parameter definition. but in the operator overloading I can see & oprator instead like the following
```
MyClass operator+(MyClass &obj) {
MyClass res;
res.var= this->var+obj.var;
return res;
}
```
what does & operator in parameter definition means? and why we accessed the obj attributes with dot operator if it is pointer? shouldn't it be -> ?

Answer 1

https://www3.ntu.edu.sg/home/ehchua/programming/cpp/cp4_PointerReference.html

C++ added the so-called reference variables (or references in short). A reference is an alias, or an alternate name to an existing variable. For example, suppose you make peter a reference (alias) to paul, you can refer to the person as either peter or paul.
The main use of references is acting as function formal parameters to support pass-by-reference. In an reference variable is passed into a function, the function works on the original copy (instead of a clone copy in pass-by-value). Changes inside the function are reflected outside the function.
A reference is similar to a pointer. In many cases, a reference can be used as an alternative to pointer, in particular, for the function parameter.

2.1 References (or Aliases) (&)
Recall that C/C++ use & to denote the address-of operator in an expression. C++ assigns an additional meaning to & in declaration to declare a reference variable.
The meaning of symbol & is different in an expression and in a declaration. When it is used in an expression, & denotes the address-of operator, which returns the address of a variable, e.g., if number is an int variable, &number returns the address of the variable number (this has been described in the above section).
Howeve, when & is used in a declaration (including function formal parameters), it is part of the type identifier and is used to declare a reference variable (or reference or alias or alternate name). It is used to provide another name, or another reference, or alias to an existing variable.
The syntax is as follow: