fixup! Add another defer exercise

This commit is contained in:
Luka Markušić
2026-06-02 06:11:27 +02:00
parent e61bedaa25
commit bd55c4ac5a
5 changed files with 42 additions and 40 deletions

View File

@@ -10,6 +10,8 @@ pub fn main() void {
for (animals) |a| printAnimal(a); for (animals) |a| printAnimal(a);
std.debug.print("done.\n", .{}); std.debug.print("done.\n", .{});
std.debug.print("Answer to everything? {d}\n", .{calculateTheUltimateQuestionOfLife()});
} }
// This function is _supposed_ to print an animal name in parentheses // This function is _supposed_ to print an animal name in parentheses
@@ -35,3 +37,24 @@ fn printAnimal(animal: u8) void {
std.debug.print("Unknown", .{}); std.debug.print("Unknown", .{});
} }
// This function is supposed to calculate the answer to the
// ultimate question of life, the universe, and everything,
// but it needs to be deferred as far in the future as possible,
// in order to gather more data.
//
// When there are multiple defers in a single block, they are executed in reverse order.
// This example might seem silly, but it's important to know when e.g.
// deinitializing containers whose elements need to be deinitialized first.
fn calculateTheUltimateQuestionOfLife() u32 {
var x: u32 = 100;
// Try reordering the statements to get the answer 42
{
defer x = x / 10;
defer x = x + 11;
defer x = x * 2;
}
return x;
}

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@@ -1,18 +0,0 @@
//
// When there are multiple defers in a single block, they are executed in reverse order.
//
const std = @import("std");
pub fn main() void {
var x: u32 = 100;
{
// Try reordering the statements to get the answer 42
defer x = x / 10;
defer x = x + 11;
defer x = x * 2;
// It might seem silly in this example, but it's important to know when
// deinitializing containers whose elements need to be deinitialized first.
}
std.debug.print("{d}\n", .{x});
}

View File

@@ -1,6 +1,6 @@
--- exercises/028_defer2.zig 2023-10-03 22:15:22.122241138 +0200 --- exercises/028_defer2.zig 2026-06-02 06:08:12.713672612 +0200
+++ answers/028_defer2.zig 2023-10-05 20:04:06.966098530 +0200 +++ answers/028_defer2.zig 2026-06-02 06:08:43.262234023 +0200
@@ -18,7 +18,7 @@ @@ -20,7 +20,7 @@
fn printAnimal(animal: u8) void { fn printAnimal(animal: u8) void {
std.debug.print("(", .{}); std.debug.print("(", .{});
@@ -9,3 +9,15 @@
if (animal == 'g') { if (animal == 'g') {
std.debug.print("Goat", .{}); std.debug.print("Goat", .{});
@@ -51,9 +51,9 @@
// Try reordering the statements to get the answer 42
{
- defer x = x / 10;
- defer x = x + 11;
defer x = x * 2;
+ defer x = x + 11;
+ defer x = x / 10;
}
return x;

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@@ -1,14 +0,0 @@
--- exercises/116_defer3.zig 2026-05-31 22:29:56.189323732 +0200
+++ answers/116_defer3.zig 2026-05-31 22:30:17.749186667 +0200
@@ -7,9 +7,9 @@
var x: u32 = 100;
{
// Try reordering the statements to get the answer 42
- defer x = x / 10;
- defer x = x + 11;
defer x = x * 2;
+ defer x = x + 11;
+ defer x = x / 10;
// It might seem silly in this example, but it's important to know when
// deinitializing containers whose elements need to be deinitialized first.

View File

@@ -693,7 +693,10 @@ const exercises = [_]Exercise{
}, },
.{ .{
.main_file = "028_defer2.zig", .main_file = "028_defer2.zig",
.output = "(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done.", .output =
\\(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done.
\\Answer to everything? 42
, // pay attention to the comma
}, },
.{ .{
.main_file = "029_errdefer.zig", .main_file = "029_errdefer.zig",
@@ -1223,10 +1226,6 @@ const exercises = [_]Exercise{
.main_file = "115_packed2.zig", .main_file = "115_packed2.zig",
.output = "", .output = "",
}, },
.{
.main_file = "116_defer3.zig",
.output = "42",
},
.{ .{
.main_file = "999_the_end.zig", .main_file = "999_the_end.zig",
.output = .output =