31 - plus opinionated convert to const

exercises/031_switch2.zig

@@ -15,7 +15,7 @@ pub fn main() void {
     const lang_chars = [_]u8{ 26, 9, 7, 42 };
 
     for (lang_chars) |c| {
-        var real_char: u8 = switch (c) {
+        const real_char: u8 = switch (c) {
             1 => 'A',
             2 => 'B',
             3 => 'C',
@@ -31,6 +31,7 @@ pub fn main() void {
             26 => 'Z',
             // As in the last exercise, please add the 'else' clause
             // and this time, have it return an exclamation mark '!'.
+            else => '!',
         };
 
         std.debug.print("{c}", .{real_char});