CPP Reference Type
[Call by Reference](https://texonom.com/call-by-reference-cd8a9f46cce34bd780a32c444ea56a34) [C Pointer](https://texonom.com/c-pointer-564e99b3e4144f638f887f1db1a34918) [Symbolic Link](https://texonom.com/symbolic-link-2c901ae724a34a5aa73ab7cc15898914) 


### Think of it as Array that has 1 element
new feature in C++
```typevoid mixedCall(int & par1, int par2, double & par3);```
- arg1 must be integer type, is passed by reference
- arg2 must be integer type, is passed by value
- arg3 must be double type, is passed by reference


## Two ways of usage
### Operator
1. address of variable when use variable
### Type
2. define reference type variable
> 1. 한번 되면 바뀔 수 없다
> 변수 alias이므로 자주 메모리 할당 필요없이 변수명만 바꿔주는 동작 

`There shall be no references to references, no arrays of references, and no pointers to references`


> [씹어먹는 C++ - <2. C++ 참조자(레퍼런스)의 도입>](https://modoocode.com/141)





