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- //
- // Enums are really just a set of numbers. You can leave the
- // numbering up to the compiler, or you can assign them
- // explicitly. You can even specify the numeric type used.
- //
- // const Stuff = enum(u8){ foo = 16 };
- //
- // You can get the integer out with a builtin function,
- // @intFromEnum(). We'll learn about builtins properly in a later
- // exercise.
- //
- // const my_stuff: u8 = @intFromEnum(Stuff.foo);
- //
- // Note how that built-in function starts with "@" just like the
- // @import() function we've been using.
- //
- const std = @import("std");
- // Zig lets us write integers in hexadecimal format:
- //
- // 0xf (is the value 15 in hex)
- //
- // Web browsers let us specify colors using a hexadecimal
- // number where each byte represents the brightness of the
- // Red, Green, or Blue component (RGB) where two hex digits
- // are one byte with a value range of 0-255:
- //
- // #RRGGBB
- //
- // Please define and use a pure blue value Color:
- const Color = enum(u32){
- red = 0xff0000,
- green = 0x00ff00,
- blue = 0x0000ff,
- };
- pub fn main() void{
- // Remember Zig's multi-line strings? Here they are again.
- // Also, check out this cool format string:
- //
- // {x:0>6}
- // ^
- // x type ('x' is lower-case hexadecimal)
- // : separator (needed for format syntax)
- // 0 padding character (default is ' ')
- // > alignment ('>' aligns right)
- // 6 width (use padding to force width)
- //
- // Please add this formatting to the blue value.
- // (Even better, experiment without it, or try parts of it
- // to see what prints!)
- std.debug.print(
- \\<p>
- \\ <span style="color: #{x:0>6}">Red</span>
- \\ <span style="color: #{x:0>6}">Green</span>
- \\ <span style="color: #{x:0>6}">Blue</span>
- \\</p>
- \\
- , .{
- @intFromEnum(Color.red),
- @intFromEnum(Color.green),
- @intFromEnum(Color.blue), // Oops! We're missing something!
- });
- }
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