Memory Address

Memory Address

Every variable lives somewhere in memory, and that location has an address. It's how the computer finds the value.

Get an address with &

The & operator gives the memory address of a variable:

int age = 30;
printf("%p", &age);

Output looks like 0x7ffe6f8d47bc - a hex number, the address in memory.

Addresses vary

The exact number depends on the machine and run - it can change between runs. What matters is the idea: each variable has a unique home.

So what's the point?

• It's how scanf stores your input (that's why you wrote &x).
• It leads to pointers, the key to C's power.
• Arrays' "decay" to an address - the array name itself is an address.

TL;DR

• &variable returns the variable's memory address.
• Use %p to print an address in C.
• Addresses are hex numbers and vary by run.
• Understanding addresses is step one toward pointers.