Welcome to XCODX Online Compiler
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Zig is a systems programming language created by Andrew Kelley in 2016 as a leaner alternative to C, with manual memory management, no hidden control flow, and no macros or preprocessor. In place of macros it offers `comptime`, a way to run ordinary Zig code at compile time for generics and configuration. As of 2026 Zig is still pre-1.0, which is worth keeping in mind: the language, and especially its standard I/O interfaces, have shifted noticeably between releases, so code written for one version can need small changes on another. The XCODX sandbox compiles and runs your program against whatever version the runtime badge reports. It is a low-friction way to try Zig's syntax and error-handling model without installing the toolchain.
const std = @import("std");
pub fn main() void {
const name = "XCODX";
var sum: u32 = 0;
var i: u32 = 1;
while (i <= 10) : (i += 1) {
sum += i;
}
std.debug.print("Hello from {s}!\n", .{name});
std.debug.print("Sum of 1..10 = {d}\n", .{sum});
}
Zig fits low-level work where you want tight control over memory and a small, explicit language — operating-system and embedded code, high-performance libraries, and cross-compilation, and it doubles as a drop-in C and C++ cross-compiler. Choose it when C's implicitness frustrates you but you do not want a large runtime or a borrow checker. The trade-off is maturity: as a pre-1.0 language its APIs move and documentation ages quickly. It is a poor fit for quick scripting or for projects that need a stable, long-term-supported standard library today, and on XCODX external packages fetched via `zig build` are unavailable.
No. The sandbox compiles a single file against the standard library only — there is no `zig build`, no `build.zig.zon` dependency fetching, no network, and no persistent filesystem. Everything you use has to come from `@import("std")`.
You get a reader from the standard library and read a line into a buffer, but the exact API depends on the version: older releases use `std.io.getStdIn().reader()`, while the 0.15 I/O overhaul moved to explicit buffered readers built on `std.fs.File.stdin()`. Check the version in the badge and match the current standard-library signatures. In the terminal the program blocks until you type a line or supply the Stdin Box, and Ctrl+D closes the stream.
Zig is pre-1.0 and its syntax and standard library change between releases, so a tutorial written for a different version can fail — the usual breakage is around I/O, `async`, and formatting functions. Compare your code against the standard library for the exact version shown in the runtime badge.
No. Zig uses manual memory management with explicit allocators that you pass around, which is why many standard-library functions take an allocator argument. For a tiny sandbox example you can often avoid the heap entirely, as the sample here does.
`comptime` runs ordinary Zig code at compile time, and it is how Zig does generics, constant folding, and type-level programming without a separate macro language. It is one of the language's defining features and works normally in the sandbox.
Whatever the runtime badge above the editor reports — the Piston backend pins a specific release. Because the language is still evolving, write against that version rather than the newest documentation you find online.
main.zigruststd.io.getStdIn()const std = @import("std");
pub fn main() !void {
const stdout = std.io.getStdOut().writer();
try stdout.print("Hello from Zig!\n", .{});
try stdout.print("Welcome to XCODX Online Compiler!\n", .{});
}