ziglings/exercises/095_for_loops.zig

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2023-03-04 10:07:53 -05:00
//
// 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.