quote
definition:
type name & reference name = a variable name
int n = 4; int &r = n;
A reference to a variable, equivalent to this variable, equivalent to an alias for the variable
Notice:
1. When defining a reference, be sure to initialize it to refer to a variable.
2. After initialization, it will always refer to the variable and will not refer to other variables
3. References can only refer to variables, not constants and expressions
application
swap two variables
void swap( int & a, int & b)
{
int tmp;
tmp = a;a = b; b = tmp;
}
as the return value of the function
int n = 4;
int & SetValue(){return n;}
often quoted
When defining a reference, add the const keyword in front of it
Can't modify the content of its citation through constant citation (but can do it in other ways)