References vs Pointers
A reference is an alias for an existing variable. Unlike pointers, references cannot be null and cannot be reassigned after initialization.
Example
int original = 42;
int& ref = original; // ref is an alias for original
cout << ref << endl; // 42
ref = 100;
cout << original << endl; // 100 (modified through reference)
// References in functions
void swap(int& a, int& b) {
int temp = a;
a = b;
b = temp;
}
int x = 10, y = 20;
swap(x, y);
cout << x << " " << y << endl; // 20 10
// Const reference — read-only alias
const int& cref = original;
// cref = 50; // Error! Cannot modify through const reference