Why does this produce an InvalidCharacter error?

[nova ivy]

const std = @import("std");

pub fn main() !void {
    var bytes: [3]u8 = .{ 0, 0, '4' };
    bytes[1] = '4';
    bytes[2] = '2';

    const val = try std.fmt.parseInt(u8, &bytes, 10);
    std.debug.print("Parsed bytes {s} as {d}\n", .{ bytes, val });
}

In this example, I am trying to construct a string of integer characters and then parse that string into a u8. However, this produces the following output:

$ zig build run                                                                                                                                                                                                                                                                                                
error: InvalidCharacter                                                                                                                                                                                                                                                                                                       
/usr/lib64/zig/9999/lib/std/fmt.zig:1763:17: 0x1072362 in charToDigit (tmp_zig)                                                                                                                                                                                                                                               
        else => return error.InvalidCharacter,                                                                                                                                                                                                                                                                                
                ^                                                                                               
<snip, message too long>

what's the correct way to build this string piece-by-piece and then later convert to an integer?

[versed junco]

0 isn't a valid digit.

'0' would be.

[nova ivy]

🤦

ofc

that was totally it!

is there a std helper that will allow me to prefill the array with 0?

[versed junco]

there is, but ** does it too

[nova ivy]

ah, I'll take a look at ** thanks

[versed junco]

var bytes: [3]u8 = .{'0'} ** 3;

I was thinking of std.mem.zeroInit but it doesn't work to initialize members of an array. std.mem.zeroes then doesn't let you supply a default. So it's really only ** here

[nova ivy]

yup, I was already ausing std.mem.zeroes, but you're right that ** is the right approach

[ripe oasis]

@memset(&bytes, '0');