1 int x = 10;

2 &x = 20; // this doesn't work

3 * (&x) = 20; // this does work

Why does line 2 &x not work but line 3 does? Because &x returns a pointer, a number representing a memory address. This is an important distinction. A pointer doesn’t hold a memory address, it holds a number that represents a memory address.

=======

No, that is not why. Note that the following does work:

int * x = 0;

and the following works, though typically yields a warning:

int * x = 20;

Line 2 fails because & doesn't give back an l-value.