From bef099fee6f5a24036d1f02fcc43fe4b849c5528 Mon Sep 17 00:00:00 2001 From: Dave Gauer Date: Sun, 30 Apr 2023 17:11:37 -0400 Subject: Renamed 095 to "for3" to match feature sequence So 100 will be the next in line. --- exercises/095_for3.zig | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 exercises/095_for3.zig (limited to 'exercises/095_for3.zig') diff --git a/exercises/095_for3.zig b/exercises/095_for3.zig new file mode 100644 index 0000000..e4c4662 --- /dev/null +++ b/exercises/095_for3.zig @@ -0,0 +1,73 @@ +// +// The Zig language is in rapid development and continuously +// improves the language constructs. Ziglings evolves with it. +// +// Until version 0.11, Zig's 'for' loops did not directly +// replicate the functionality of the C-style: "for(a;b;c)" +// which are so well suited for iterating over a numeric +// sequence. +// +// Instead, 'while' loops with counters clumsily stood in their +// place: +// +// var i: usize = 0; +// while (i < 10) : (i += 1) { +// // Here variable 'i' will have each value 0 to 9. +// } +// +// But here we are in the glorious future and Zig's 'for' loops +// can now take this form: +// +// for (0..10) |i| { +// // Here variable 'i' will have each value 0 to 9. +// } +// +// The key to understanding this example is to know that '0..9' +// uses the new range syntax: +// +// 0..10 is a range from 0 to 9 +// 1..4 is a range from 1 to 3 +// +// At the moment, ranges are only supported in 'for' loops. +// +// Perhaps you recall Exercise 13? We were printing a numeric +// sequence like so: +// +// 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}); +// } +// +// Let's try out the new form of 'for' to re-implement that +// exercise: +// +const std = @import("std"); + +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", .{}); +} +// +// That's a bit nicer, right? +// +// Of course, both 'while' and 'for' have different advantages. +// Exercises 11, 12, and 14 would NOT be simplified by switching +// a 'while' for a 'for'. -- cgit v1.2.3