ziglings/exercises/016_for2.zig
2021-04-10 14:45:25 -04:00

36 lines
1.2 KiB
Zig

//
// For loops also let you store the "index" of the iteration - a
// number starting with 0 that counts up with each iteration:
//
// for (items) |item, index| {
//
// // Do something with item and index
//
// }
//
// You can name "item" and "index" anything you want. "i" is a popular
// shortening of "index". The item name is often the singular form of
// the items you're looping through.
//
const std = @import("std");
pub fn main() void {
// Let's store the bits of binary number 1101 in
// 'little-endian' order (least significant byte first):
const bits = [_]u8{ 1, 0, 1, 1 };
var value: u32 = 0;
// Now we'll convert the binary bits to a number value by adding
// the value of the place as a power of two for each bit.
//
// See if you can figure out the missing piece:
for (bits) |bit, ???| {
// Note that we convert the usize i to a u32 with
// @intCast(), a builtin function just like @import().
// We'll learn about these properly in a later exercise.
var place_value = std.math.pow(u32, 2, @intCast(u32, i));
value += place_value * bit;
}
std.debug.print("The value of bits '1101': {}.\n", .{value});
}