If / else that return values

In Zig, an if/else block can return a value that’s assigned to a variable or constant. However - it must be used as a simple expression, without {} braces for the block definitions:

if_else_return.zig

const std = @import("std");

const print = std.debug.print;

pub fn main() void {

const n_age = 18;

const s_response = if (n_age < 18) "underage" else "an adult";

print("You are {s}\n", .{s_response});

}

$ zig run if_else_return.zig

You are an adult

When returning a value from an if/else, it’s very useful for assigning a value based on a condition in a compact way.

In this example, the value assigned to s_response is determined by the condition and remains an immutable constant. Immutable means it can’t be changed, and it’s a good programming practice: in many cases, preventing a value from being modified after assignment helps avoid hard-to-find bugs.