exercise for new for-loops

This commit is contained in:
Chris Boesch 2023-03-04 16:07:53 +01:00
parent 582f3b1b09
commit 101151f3f1
4 changed files with 75 additions and 3 deletions

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@ -42,7 +42,7 @@ Verify the installation and build number of `zig` like so:
```bash
$ zig version
0.11.0-dev.1711+xxxxxxxxx
0.11.0-dev.1844+xxxxxxxxx
```
Clone this repository with Git:
@ -82,7 +82,7 @@ about input:
### Version Changes
Version-0.11.0-dev.1711+xxxxxxxxx
Version-0.11.0-dev.1844+xxxxxxxxx
* *2023-02-21* zig 0.11.0-dev.1711 - changes in `for loops` - new: Multi-Object For-Loops + Struct-of-Arrays
* *2023-02-12* zig 0.11.0-dev.1638 - changes in `std.Build` cache_root now returns a directory struct
* *2023-02-04* zig 0.11.0-dev.1568 - changes in `std.Build` (combine `std.build` and `std.build.Builder` into `std.Build`)

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@ -8,7 +8,7 @@ const print = std.debug.print;
// When changing this version, be sure to also update README.md in two places:
// 1) Getting Started
// 2) Version Changes
const needed_version = std.SemanticVersion.parse("0.11.0-dev.1711") catch unreachable;
const needed_version = std.SemanticVersion.parse("0.11.0-dev.1844") catch unreachable;
const Exercise = struct {
/// main_file must have the format key_name.zig.
@ -479,6 +479,10 @@ const exercises = [_]Exercise{
.output = "The normalized angle of 765.2 degrees is 45.2 degrees.",
.C = true,
},
.{
.main_file = "095_for_loops.zig",
.output = "1 2 4 7 8 11 13 14 16 17 19",
},
.{
.main_file = "999_the_end.zig",
.output = "\nThis is the end for now!\nWe hope you had fun and were able to learn a lot, so visit us again when the next exercises are available.",

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@ -0,0 +1,64 @@
//
// The Zig language is in rapid development and continuously improves
// the language constructs steadily.
//
// Since version 0.11, the "for-loops" widely used in other languages
// such as C, e.g. "for (int i = 0; i < 10..." can now also be formed
// similarly in Zig, which previously required a "while" construct.
// Similar in this case actually means better, just as Zig generally
// tries to make everything simple and "better".
//
// These new "for-loops" look like the following in Zig:
//
// for (0..10) |idx| {
// // In this case 'idx' takes all values from 0 to 9.
// }
//
// This is really simple and can replace the previous, somewhat bulky:
//
// var idx: usize = 0;
// while (idx < 10) : (idx += 1) {
// // Again, idx takes all values from 0 to 9.
// }
//
// This would also simplify exercise 13, for example.
// The best way to try this out is to use this exercise, which in the
// original looks like this:
//
// ...
// var n: u32 = 1;
//
// // I want to print every number between 1 and 20 that is NOT
// // divisible by 3 or 5.
// 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 % 5 == 0) continue;
// std.debug.print("{} ", .{n});
// }
// ...
//
const std = @import("std");
// And now with the new "for-loop".
pub fn main() void {
// I want to print every number between 1 and 20 that is NOT
// divisible by 3 or 5.
for (???) |n| {
// The '%' symbol is the "modulo" operator and it
// returns the remainder after division.
if (n % 3 == 0) continue;
if (n % 5 == 0) continue;
std.debug.print("{} ", .{n});
}
std.debug.print("\n", .{});
}
// Is actually a little easier. The interesting thing here is that the other
// previous 'while' exercises (11,12, 14) cannot be simplified by this
// new "for-loop". Therefore it is good to be able to use both variations
// accordingly.

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@ -0,0 +1,4 @@
49c49
< for (???) |n| {
---
> for (1..21) |n| {