zig/doc/langref/test_null_terminated_array.zig

const std = @import("std");
const expectEqual = std.testing.expectEqual;

test "0-terminated sentinel array" {
    const array = [_:0]u8{ 1, 2, 3, 4 };

    try expectEqual([4:0]u8, @TypeOf(array));
    try expectEqual(4, array.len);
    try expectEqual(0, array[4]);
}

test "extra 0s in 0-terminated sentinel array" {
    // The sentinel value may appear earlier, but does not influence the compile-time 'len'.
    const array = [_:0]u8{ 1, 0, 0, 4 };

    try expectEqual([4:0]u8, @TypeOf(array));
    try expectEqual(4, array.len);
    try expectEqual(0, array[4]);
}

// test