+++ title = "1. Variables and Constants" weight = 1 +++

1. Variables and Constants {#1-variables-and-constants}

Zen C distinguishes between compile-time constants and runtime variables.

Manifest Constants (def)

Values that exist only at compile-time (folded into code). Use these for array sizes, fixed configuration, and magic numbers.

def MAX_SIZE = 1024;
let buffer: char[MAX_SIZE]; // Valid array size

Variables (let)

Storage locations in memory. Can be mutable or read-only (const).

let x = 10;             // Mutable
x = 20;                 // OK

let y: const int = 10;  // Read-only (Type qualified)
// y = 20;              // Error: cannot assign to const

{% alert(type="tip") %} Type Inference: Zen C automatically infers types for initialized variables. It compiles to C23 auto on supported compilers, or GCC's __auto_type extension otherwise. {% end %}