exercises/001_hello.zig

@@ -16,6 +16,6 @@
 //
 const std = @import("std");
 
-pub fn main() void {
+fn main() void {
     std.debug.print("Hello world!\n", .{});
 }

exercises/002_std.zig

@@ -11,7 +11,7 @@
 // Please complete the import below:
 //
 
-const std = @import("std");
+??? = @import("std");
 
 pub fn main() void {
     std.debug.print("Standard Library.\n", .{});

exercises/003_assignment.zig

@@ -34,12 +34,12 @@
 const std = @import("std");
 
 pub fn main() void {
-    var n: u8 = 50;
+    const n: u8 = 50;
     n = n + 5;
 
-    const pi: u32 = 314159;
+    const pi: u8 = 314159;
 
-    const negative_eleven: i8 = -11;
+    const negative_eleven: u8 = -11;
 
     // There are no errors in the next line, just explanation:
     // Perhaps you noticed before that the print function takes two

exercises/004_arrays.zig

@@ -27,7 +27,7 @@ pub fn main() void {
     // (Problem 1)
     // This "const" is going to cause a problem later - can you see what it is?
     // How do we fix it?
-    var some_primes = [_]u8{ 1, 3, 5, 7, 11, 13, 17, 19 };
+    const some_primes = [_]u8{ 1, 3, 5, 7, 11, 13, 17, 19 };
 
     // Individual values can be set with '[]' notation.
     // Example: This line changes the first prime to 2 (which is correct):
@@ -40,11 +40,11 @@ pub fn main() void {
     // (Problem 2)
     // Looks like we need to complete this expression. Use the example
     // above to set "fourth" to the fourth element of the some_primes array:
-    const fourth = some_primes[3];
+    const fourth = some_primes[???];
 
     // (Problem 3)
     // Use the len property to get the length of the array:
-    const length = some_primes.len;
+    const length = some_primes.???;
 
     std.debug.print("First: {}, Fourth: {}, Length: {}\n", .{
         first, fourth, length,

exercises/005_arrays2.zig

@@ -25,12 +25,12 @@ pub fn main() void {
     // (Problem 1)
     // Please set this array concatenating the two arrays above.
     // It should result in: 1 3 3 7
-    const leet = le ++ et;
+    const leet = ???;
 
     // (Problem 2)
     // Please set this array using repetition.
     // It should result in: 1 0 0 1 1 0 0 1 1 0 0 1
-    const bit_pattern = [_]u8{ 1, 0, 0, 1 } ** 3;
+    const bit_pattern = [_]u8{ ??? } ** 3;
 
     // Okay, that's all of the problems. Let's see the results.
     //

exercises/006_strings.zig

@@ -24,18 +24,18 @@ pub fn main() void {
     // (Problem 1)
     // Use array square bracket syntax to get the letter 'd' from
     // the string "stardust" above.
-    const d: u8 = ziggy[4];
+    const d: u8 = ziggy[???];
 
     // (Problem 2)
     // Use the array repeat '**' operator to make "ha ha ha ".
-    const laugh = "ha " ** 3;
+    const laugh = "ha " ???;
 
     // (Problem 3)
     // Use the array concatenation '++' operator to make "Major Tom".
     // (You'll need to add a space as well!)
     const major = "Major";
     const tom = "Tom";
-    const major_tom = major ++ " " ++ tom;
+    const major_tom = major ??? tom;
 
     // That's all the problems. Let's see our results:
     std.debug.print("d={u} {s}{s}\n", .{ d, laugh, major_tom });

exercises/007_strings2.zig

@@ -15,9 +15,9 @@ const std = @import("std");
 
 pub fn main() void {
     const lyrics =
-        \\Ziggy played guitar
+        Ziggy played guitar
-        \\Jamming good with Andrew Kelley
+        Jamming good with Andrew Kelley
-        \\And the Spiders from Mars
+        And the Spiders from Mars
     ;
 
     std.debug.print("{s}\n", .{lyrics});

exercises/008_quiz.zig

@@ -19,7 +19,7 @@ pub fn main() void {
     // the idiomatic type to use for array indexing.
     //
     // There IS a problem on this line, but 'usize' isn't it.
-    var x: usize = 1;
+    const x: usize = 1;
 
     // Note: When you want to declare memory (an array in this
     // case) without putting anything in it, you can set it to
@@ -33,10 +33,10 @@ pub fn main() void {
     lang[0] = letters[x];
 
     x = 3;
-    lang[1] = letters[x];
+    lang[???] = letters[x];
 
-    x = 5;
+    x = ???;
-    lang[2] = letters[x];
+    lang[2] = letters[???];
 
     // We want to "Program in Zig!" of course:
     std.debug.print("Program in {s}!\n", .{lang});

exercises/009_if.zig

@@ -24,7 +24,7 @@ pub fn main() void {
     const foo = 1;
 
     // Please fix this condition:
-    if (foo == 1) {
+    if (foo) {
         // We want our program to print this message!
         std.debug.print("Foo is 1!\n", .{});
     } else {

exercises/010_if2.zig

@@ -10,7 +10,7 @@ pub fn main() void {
 
     // Please use an if...else expression to set "price".
     // If discount is true, the price should be $17, otherwise $20:
-    const price: u8 = if (discount) 17 else 20;
+    const price: u8 = if ???;
 
     std.debug.print("With the discount, the price is ${}.\n", .{price});
 }

exercises/011_while.zig

@@ -21,7 +21,7 @@ pub fn main() void {
     var n: u32 = 2;
 
     // Please use a condition that is true UNTIL "n" reaches 1024:
-    while (n < 1024) {
+    while (???) {
         // Print the current number
         std.debug.print("{} ", .{n});
 

exercises/012_while2.zig

@@ -25,7 +25,7 @@ pub fn main() void {
 
     // Please set the continue expression so that we get the desired
     // results in the print statement below.
-    while (n < 1000) : (n *= 2) {
+    while (n < 1000) : ??? {
         // Print the current number
         std.debug.print("{} ", .{n});
     }

exercises/013_while3.zig

@@ -24,8 +24,8 @@ pub fn main() void {
     while (n <= 20) : (n += 1) {
         // The '%' symbol is the "modulo" operator and it
         // returns the remainder after division.
-        if (n % 3 == 0) continue;
+        if (n % 3 == 0) ???;
-        if (n % 5 == 0) continue;
+        if (n % 5 == 0) ???;
         std.debug.print("{} ", .{n});
     }
 

exercises/014_while4.zig

@@ -18,7 +18,7 @@ pub fn main() void {
     // Oh dear! This while loop will go forever?!
     // Please fix this so the print statement below gives the desired output.
     while (true) : (n += 1) {
-        if (n == 4) break;
+        if (???) ???;
     }
 
     // Result: we want n=4