What does this Zig snippet output?

1const std = @import("std");
2pub fn main() void {
3    const arr = [_]u8{ 1, 2, 3 };
4    const repeated = arr ++ arr;
5    std.debug.print("{d}\n", .{repeated.len});
6    std.debug.print("{d}\n", .{repeated[4]});
7}