*T를 사용하는 단일 항목 포인터

A pointer holds the address of a value living somewhere else in memory, instead of holding the value itself. 📍

A single-item pointer has the type *T, where T is what it points at. So *i32 means a pointer to one i32 value.

Use the & operator in front of a variable to get a pointer to it. The result is the address where that value is stored.

A single-item pointer guarantees it refers to exactly one value, not an array. The compiler tracks that for you.

A pointer is just an address, so its size is the machine word, not the size of T. Pointing at a huge struct still costs one address.

A plain *T lets you both read and write the value it points to. You will add const later to make it read-only.

Passing a pointer to a function shares the original value, so changes made through it are visible to the caller.

Taking &x on a const gives you a *const i32, because Zig will not let you write through a pointer to immutable data.

An ordinary Zig pointer can never be null. If a value might be missing you must use an optional pointer like ?*T.

When you write const p = &x, Zig infers the pointer type from x, so you rarely have to spell out *i32 by hand.

Pointers let you modify a value in place and avoid copying large data, which is core to Zig's explicit low-level control.

You want a function to change a caller's variable. What type should the parameter be?

A single-item pointer *T holds the address of exactly one value, is taken with &, is never null, and lets you share data instead of copying it. 🎯