When to use the ampersand operator

- If you really want to get down and dirty…with pointers in C,…you need to embrace two unary operators,…the ampersand and the asterisk.…This movie covers the ampersand.…A later movie covers the asterisk.…Also, of the two, the ampersand causes less trouble,…although it can be confusing.…The ampersand is the address of operator.…It returns the memory location of a variable,…and that's the only way it's used,…prefixed to a variable like the engine on a train.…The variable doesn't even have to be initialized,…just declared.…

Open exercise 05-01_ampersand1.…This code declares four variables,…a, b, c, and d,…each of a different type.…When a variable is declared,…it's given a location in memory.…To fetch that address, you use the ampersand operator.…The printf statement displays those addresses.…The %p placeholder is used…and the & fetches the address.…Build and run this code.…The addresses you see on your screen…will be different from what you see here.…

Each computer shows not only a different location,…but perhaps a different format for the numbers.…